Malaysian troops backed by fighter jets have attacked an armed Filipino group, trying to end a standoff on Borneo island after violence that killed at least 27 people and sparked fears of broader insecurity in the resource-rich region.
Planes bombed the area in eastern Sabah state on Tuesday for more than 30 minutes before hundreds of ground troops moved in to search for around 180 members of the self-proclaimed Royal Sulu Army believed to be hiding near a coastal palm-oil plantation, Malaysian officials said.
The armed group, who hail from the southern Philippines, landed in a coastal village in Sabah on February 9 to claim the territory as their own, citing ownership documents from the late 1800s.
Police inspector general Ismail Omar told reporters the mission's goals had been accomplished and there were no Malaysian casualties, without giving further details.
Relatives of the group who have been in touch with the gunmen by phone from Manila said they had survived the bombardment.
"They are safe, they are intact," Abraham Idjirani, a spokesman for the group, told Philippine television.
The violence has sparked a political crisis ahead of elections in Malaysia as well as the Philippines. Both governments say they are investigating allegations of opposition involvement.
Dozens of people have been protesting outside the Malaysian embassy in the Philippines capital Manila in support of the group in Sabah.
Malaysian Prime Minister Najib Razak, who faces a tough election within weeks, has come under pressure to take a firm stance against the group, which arrived by boat about three weeks ago claiming to be descendants of the southern Philippines' sultanate of Sulu.
The insecurity has disrupted operations in Sabah's huge palm oil industry and prolonged trouble could dampen growing investor interest in energy and infrastructure projects in the state, although the main oil fields are far from the trouble.
Oil majors such as ConocoPhillips and Shell have poured in billions of dollars to develop oil and gas fields in Sabah. Chinese companies have been investing in hydro-power and coal mining.
Two policemen were killed along with 12 fighters when Malaysian security forces tried to tighten a cordon around the group on Friday, sparking more violence over the weekend.
"The longer this invasion lasts, it is clear to the authorities that the invaders do not intend to leave Sabah," Najib said on Tuesday, adding that negotiations with the estimated 100 to 300 members of the group had gone nowhere.
"The government must take action to safeguard the dignity and sovereignty of the country as required by the people."
The violence presents Najib with a security headache that could delay an election that must be held by June, adding to nervousness among investors over what could be the country's closest ever polls.
The Royal Sulu Army are demanding an increased payment from Malaysia for their claim as the rightful owners of Sabah.
The Malaysian government continues to pay the Kiram clan of Sulu a supposed annual rent of $1,500 for the use of more than 73,000 square kilometres of land in Sabah.
Malaysia has refused their demands and, along with the Philippine government, has urged the group to return home.
The violence has sparked a political crisis ahead of elections for both the Philippine and Malaysian governments and raised concerns of instability in resource-rich Sabah state.
The crisis also comes a crucial stage of peace negotiations arranged by Malaysia between the Philippine government and the Moro Islamic Liberation Front, the largest Muslim rebel group in the southern Philippines.
The group has ignored appeals from Aquino to leave Sabah or face prosecution at home on charges of triggering armed conflict.