The West Papua Liberation Army is claiming responsibility for the killings of at least 24 Indonesian construction workers in Papua.

Photo: Supplied

The claims confirmed initial blame placed on the separatist group by Indonesian authorities, and marked a deadly escalation of conflict in the restive region unseen in recent years.

Indonesian media reported on Tuesday that around 150 Indonesian armed forces were in pursuit of the gunmen, after President Joko Widodo ordered military and police chiefs to check in on the situation.

Witness reports described to RNZ Pacific by officials painted a grim picture of a civilian massacre which took place atop a hilltop in Tolikara regency on Sunday.

On Saturday, as members of the Liberation Army held a ceremony in neighbouring Nduga to commemorate Papua's independence from Dutch colonial rule on December 1st, 1961, a construction worker nearby snapped a photo of the scene.

The employees of the state-owned company Istaka Karya were building bridges and roads in Papua, where Jakarta has been undertaking an infrastructure drive.

But the Liberation Army, which claimed responsibility for the attack on Tuesday, described the workers as armed members of Indonesia's military, or TNI, disguised as civilians.

The presence of a camera prompted a violent reaction from the group of around 50 Liberation Army fighters, who rounded up dozens of workers, bound their hands and marched them North, to Lanny Jaya regency, said TNI spokesperson Mohammed Aidi.

On Sunday morning, the workers were taken to the top of a hill and forced to march in formation, while they were shot at by Liberation Army soldiers, who killed at least 19 people.

Eleven employees managed to survive the massacre by pretending they were dead, said Mr Aidi. But when they ran, the group was pursued by the Liberation Army and 5 more were killed with bow and arrows and spears.

Survivors took refuge at a TNI outpost, where soldiers returned fire at the Liberation Army. One soldier died in the shootout.

Four workers were evacuated by police and military on Tuesday, along with eight local health centre staff and teachers employed by TNI, said Mr Aidi. Three workers have been hospitalised with gunshot wounds, while another two who escaped remained missing.

President Widodo said on Tuesday he would visit Papua once more information on the incident became available.

Photo: AFP

"We realize that even though the development in Papua is indeed very difficult to carry out and can still be hindered by incidents such as the reported one, the development in Papua should continue," he said.

In February, the Liberation Army made a fresh declaration of war against the TNI, which it called "the invaders".

Since then, the group has been involved in a spate of skirmishes in Papua, including a series of deadly gunfire exchanges in the Highlands regencies of Puncak Jaya, Nduga, Timika and Lanny Jaya.

Two Liberation Army members were killed by TNI in November when they exchanged gunfire in Lanny Jaya.

Five others were killed in Puncak Jaya in October by the Indonesian military, it said.

In late October, Indonesian media reported that a group of 15 school teachers and medical workers were held hostages by the Liberation Army in Nduga for two weeks, and that one teacher was raped.</s>About 300 West Papuan demonstrators calling for independence for the restive Indonesian region faced off with counterprotesters Saturday in the country's second-largest city.

The demonstrators in Surabaya chanted "Freedom Papua" and held banners demanding a referendum for independence to mark Dec. 1, which many West Papuans consider the anniversary of what they say should have been their independence.

"We are demanding the truth of our history," a speaker shouted at the crowd at the rally, which was organized by the Papua Students Alliance. "Referendum for independence is the right solution for the people of Papua."

The crowd, including many wearing headbands with the morning star flag as a separatist group symbol, was blocked from marching to the city center by scores of counterprotesters from several youth organizations in Surabaya, the capital of East Java province. Some confronted the pro-independence protesters with sharpened bamboos.

"You may rally to voice your aspiration, but don't bring the separatist issue," said a speaker from the rival group. "Papua is a part of Indonesia forever, and we are willing to die to defend the unitary state of Indonesia."

Members of the two camps pushed each other, but several hundred anti-riot police prevented the two groups from clashing, said East Java police spokesman Frans Barung Mangera.

The protest ended after about two hours. No one was detained by police, Mangera said.

The Free Papua Movement, a separatist group in Indonesia's restive Papua province, declared independence from Dutch rule on Dec. 1, 1961. That was rejected by the Dutch and later by Indonesia.

Papua, a former Dutch colony in the western part of New Guinea, was incorporated into Indonesia in 1969 after a U.N.-sponsored ballot that was seen as a sham by many. A small, poorly armed separatist group has been battling for independence since then.

For years, a low-level insurgency has plagued the mineral-rich region, which is ethnically and culturally distinct from much of Indonesia.

Indonesia's government, which for decades had a policy of sending Javanese and other Indonesians to settle in Papua, is now also trying to spur economic development to dampen the separatist movement.</s>SURABAYA, Indonesia (AP) - About 300 West Papuan demonstrators calling for independence for the restive Indonesian region faced off with counterprotesters Saturday in the country's second-largest city.

The demonstrators in Surabaya chanted "Freedom Papua" and held banners demanding a referendum for independence to mark Dec. 1, which many West Papuans consider the anniversary of what they say should have been their independence.

"We are demanding the truth of our history," a speaker shouted at the crowd at the rally, which was organized by the Papua Students Alliance. "Referendum for independence is the right solution for the people of Papua."

The crowd, including many wearing headbands with the morning star flag as a separatist group symbol, was blocked from marching to the city center by scores of counterprotesters from several youth organizations in Surabaya, the capital of East Java province. Some confronted the pro-independence protesters with sharpened bamboos.

"You may rally to voice your aspiration, but don't bring the separatist issue," said a speaker from the rival group. "Papua is a part of Indonesia forever, and we are willing to die to defend the unitary state of Indonesia."

Members of the two camps pushed each other, but several hundred anti-riot police prevented the two groups from clashing, said East Java police spokesman Frans Barung Mangera.

A Papuan activist with his forehead painted with banned separatist flag the "Morning Star" marches with others during a rally commemorating the 57th anniversary of the failed efforts by Papuan tribal chiefs to declare independence from Dutch colonial rule, in Surabaya, East Java, Indonesia, Saturday, Dec. 1, 2018. Indonesia took over West Papua from Dutch colonial rule in 1963 and formalized its sovereignty over the region in 1969 through a vote by about 1,000 community leaders, which critics dismissed as a sham. A separatist group called the "Free Papua Movement" has battled Indonesian rule ever since. (AP Photo/Trisnadi)

The protest ended after about two hours. No one was detained by police, Mangera said.

The Free Papua Movement, a separatist group in Indonesia's restive Papua province, declared independence from Dutch rule on Dec. 1, 1961. That was rejected by the Dutch and later by Indonesia.

Papua, a former Dutch colony in the western part of New Guinea, was incorporated into Indonesia in 1969 after a U.N.-sponsored ballot that was seen as a sham by many. A small, poorly armed separatist group has been battling for independence since then.

For years, a low-level insurgency has plagued the mineral-rich region, which is ethnically and culturally distinct from much of Indonesia.

Indonesia's government, which for decades had a policy of sending Javanese and other Indonesians to settle in Papua, is now also trying to spur economic development to dampen the separatist movement.

Papuan activists with face painted with banned separatist flag the "Morning Star" shout slogans during a rally commemorating the 57th anniversary of the failed efforts by Papuan tribal chiefs to declare independence from Dutch colonial rule, in Surabaya, East Java, Indonesia, Saturday, Dec. 1, 2018. Indonesia took over West Papua from Dutch colonial rule in 1963 and formalized its sovereignty over the region in 1969 through a vote by about 1,000 community leaders, which critics dismissed as a sham. A separatist group called the "Free Papua Movement" has battled Indonesian rule ever since. (AP Photo/Trisnadi)</s>SURABAYA, Indonesia (AP) - About 300 West Papuans have faced off with counterprotesters in Indonesia's second largest city in a rally calling for the restive region's independence.

The rally was organized by the Papua Students Alliance. The demonstrators chanted "Freedom Papua" in Surabaya city to mark Dec. 1, which many West Papuans consider as the anniversary of what should have been their independence.

The crowd, many of whom wearing headbands of a separatist flag, was blocked from marching to the city center by scores of counterprotesters from several youth organizations. They confronted the pro-independence protesters with sharpened bamboos.

Several hundred members of anti-riot police prevented the two rival groups from clashing.

The protest ended after about two hours.

A Papuan activist with his forehead painted with banned separatist flag the "Morning Star" marches with others during a rally commemorating the 57th anniversary of the failed efforts by Papuan tribal chiefs to declare independence from Dutch colonial rule, in Surabaya, East Java, Indonesia, Saturday, Dec. 1, 2018. Indonesia took over West Papua from Dutch colonial rule in 1963 and formalized its sovereignty over the region in 1969 through a vote by about 1,000 community leaders, which critics dismissed as a sham. A separatist group called the "Free Papua Movement" has battled Indonesian rule ever since. (AP Photo/Trisnadi)

Papuan activists with face painted with banned separatist flag the "Morning Star" shout slogans during a rally commemorating the 57th anniversary of the failed efforts by Papuan tribal chiefs to declare independence from Dutch colonial rule, in Surabaya, East Java, Indonesia, Saturday, Dec. 1, 2018. Indonesia took over West Papua from Dutch colonial rule in 1963 and formalized its sovereignty over the region in 1969 through a vote by about 1,000 community leaders, which critics dismissed as a sham. A separatist group called the "Free Papua Movement" has battled Indonesian rule ever since. (AP Photo/Trisnadi)
At least 19 people are killed as armed group linked to West Papua Liberation Organization attacks construction workers at Trans Papua road project in Nduga Regency, Papua, Indonesia.