Media playback is unsupported on your device Media caption A series of explosions could be seen at the dump throughout Wednesday night

Some 20,000 people are being evacuated after a series of explosions at a massive arms depot in eastern Ukraine described by officials as sabotage.

The base in Balakliya, near Kharkiv, is around 100km (60 miles) from fighting against Russian-backed separatists.

The dump is used to store thousands of tonnes of ammunition including missiles and artillery weapons.

Rescue teams are overseeing a huge evacuation effort for people living in the city and nearby villages.

The total area of the dump spans more than 350 hectares, the military says.

Everyone within a 10km (6 miles) radius of the dump is being evacuated, the Interfax news agency quoted an aide to President Petro Poroshenko as saying.

Munitions from the depot are used to supply military units in the conflict zone in nearby Luhansk and Donetsk, reports say.

Image copyright EPA Image caption A huge cloud of smoke could be seen billowing above the ammunition depot of the Ukrainian armed forces on Thursday

Image copyright DSNS Image caption By daylight smoke billowed across the sky in Balakliya

The authorities are investigating various ways the explosions may have been caused, Defence Minister Stepan Poltorak said, including the possibility of an explosive device being dropped from a drone.

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A drone was reported to have been used an earlier attempt to set the facility on fire in December 2015.

Mr Poltorak said that there were no reports that civilians or serviceman had been killed or injured in the latest incident and that airspace had been closed within a 50km (31 miles) radius of Balakliya.

More than 9,700 people have died in the conflict which erupted in 2014 when Russia annexed Ukraine's southern Crimea peninsula. Pro-Russian rebels later launched an insurgency in the east.</s>The Ukrainian military said unknown saboteurs blew up a warehouse storing tank ammunition at a military base in the east of the country early on Thursday.

The base, which contained about 138,000 tonnes of ammunition including rockets and tank ammunition, is located in the city of Balakleya about 100 km (60 miles) from the frontline of Ukraine's war against Russian-backed separatists.

Rescue teams were helping residents nearby villages in the eastern Kharkiv region, the military said, and up to 20,000 were evacuated.

Ukraine's chief military prosecutor Anatoly Matios said: 'According to preliminary data, as a result of sabotage, last night at 2.46am, fire and explosions caused the detonation of ammunition at several sites storing rockets and artillery weapons.'

Military spokesman Oleksander Motuzyanyk said security around other bases was being beefed up.

Ukrainian Prime Minister Volodymyr Groysman was due to fly to the area later on Thursday, but nobody is thought to have been hurt in the incident.

Saboteurs previously tried to destroy the same base using drones in 2015, another military spokesman, Yuzef Venskovich, told the 112 TV channel.

More than 10,000 people have been killed in the conflict between Ukraine and the separatist rebels since 2014.
A series of explosions on a military base near the Ukrainian city of Balakliya forces thousands to be evacuated from their homes.