UPDATE 3:19 p.m. EDT: Fifteen people have now died in the Turkish mine disaster, the Associated Press reported, citing Turkey’s disaster management center.

An explosion and fire at a coal mine in western Turkey killed at least five people and trapped about 300 others.

The accident occurred some 2 kilometers (1.24 miles) deep inside the mine in the town of Soma -- about 250 kilometers (155 miles) south of Istanbul -- after a power distribution unit exploded on Tuesday afternoon, Soma administrator Mehmet Bahattin Atci told the Associated Press. The miners "died of choking and burns,"  local military police Muzaffer Yurttas told broadcaster NTV.

The mayor for Manisa province said the death toll stood at five and that at least 25 people were evacuated alive. Union officials said the blast occurred during a change of shifts, resulting in uncertainty about exactly how many miners were still inside, Reuters reported.

“It is a serious accident,” Energy Minister Taner Yildiz told reporters before leaving to oversee the Soma rescue operation. “Our priority is to reach our miner brothers ... any figure we give could well be wrong.”

In a statement, Soma Komur Isletmeleri A.S., which owns the mine, said the accident occurred despite its “highest safety measures and constant controls” and said an investigation was being launched.

“Our main priority is to get our workers out so that they may be reunited with their loved ones,” the company said in a statement.

Mining accidents are common in Turkey, which has poor safety conditions. Turkey's worst mining disaster occurred in 1992 when a gas explosion killed 263 workers near the Black Sea port of Zonguldak.