Ukraine munitions depot fire
© Роман Чуловский/YouTube
Thousands of people are being evacuated from Balakleya in the Kharkov region of Ukraine, as a massive fire has broken out at a munitions depot, which is said to be the largest in the country. There are reports of explosions and shattered windows.

Chaotic scenes with hundreds of vehicles stuck in traffic jams were reported on social media after the Balakleya city administration ordered an emergency evacuation of most of the city.

Videos uploaded by local residents show a huge blaze with what appears to be a missile flying off in a random direction and falling to the ground, as detonations are heard in the background.

Most of the population of Balakleya have been evacuated, the civil defense department of the city's district administration told RIA Novosti.

"The first wave of the evacuation has come to an end, most of the population have been evacuated by buses. Now the buses are returning to evacuate the rest. Specialists are going from house to house checking who remains," the district administration said.

There have been no immediate reports of any civilian casualty.

More than 16,000 people have been evacuated from the city of Balakleya, home to 29,000 people, the Ukrainian Emergency Ministry reported. Over 3,500 people were also evacuated from nearby villages.

A seven-kilometer (4.3-mile) safety zone has been set up around the burning depot, RIA Novosti reports, citing a Ukrainian military prosecutor.

Anatoly Matios, the chief military prosecutor of Ukraine, wrote on Facebook that according to preliminary data, the explosion and fire were caused by sabotage at 3am local time at several storage sites for rocket and artillery weapons (including 125mm and 152mm tank and artillery shells). Matios said the incident was the direct result of sabotage.

An investigation has been launched.

Nearly 140,000 tons of ammunition are stored at the depot in Balakleya, the chief military prosecutor of Ukraine said on Thursday.

"The total area of the arsenal is 368 hectares, with 138,000 tons of ammunition... An unmanned aerial vehicle (UAV) is getting ready for takeoff to establish the actual extent of the arsenal affected by the explosions," Matios wrote on Facebook.

Ukraine's border service has stepped up control measures in the country's southeast due to the incident.

"The state border service has tightened the border control regime in the east-south direction," Matios wrote on Facebook.

As residents hastily flee the area, RIA Novosti Ukraine reports that mobile networks in the city are overloaded or offline.