Turkey ? A methane gas explosion ripped through a coal mine in western Turkey Thursday evening, killing at least nine miners and trapping several others, authorities said.

Gov. Selahattin Hatipoglu said at least nine were killed after the blast caused a shaft to collapse at the mine in the village of Odakoy in western Balikesir province, the semiofficial Anatolia news agency reported.

Several other miners were still believed trapped inside the mine, but the exact number was not clear.

Seven miners who were participating in rescue efforts were hospitalized with methane gas poisoning, private NTV television said.

The explosion took place nearly 500 feet below ground, Anatolia quoted Erhan Otakoylu, the owner of the private coal mine, as saying.