A major highway connecting Moscow and the Ukrainian city of Simferopol has been sealed off after explosions tore through an arms depot in south Ukraine on Thursday, sending ammunition and shrapnel flying across a 10-km (six-mile) radius and prompting the evacuation of nearly 10,000 residents, Russian media reported.

There are varying reports on casualties: several Russian agencies have said there were numerous casualties, without naming the figures, while Reuters, citing the Emergency Ministry, has said no casualties have been reported.

No Russian casualties have been reported so far, although some of the towns that were evacuated are close to the Russian border west of the region.

“A fire broke out at Defense Ministry warehouses near Novobohdanivka village, where large amounts of ammunition were stored. The ammunition then detonated,” ministry spokesman Oleh Oleksandriv told Reuters.

Reuters quoted Oleksandriv as saying that metal shards had been catapulted over a 10-km radius and hundreds of firefighters were trying to bring the blaze under control. The ministry and local authorities evacuated 9,700 people from 15 villages.

According to Reuters, reporters in the region said they had been halted about 20 km from the site of the accident, but could hear a succession of blasts and saw large plumes of black smoke.