Eight suspects have been arrested by a Turkish court in the western town of Soma, on a provisional charge of "causing multiple deaths" in last week's mine disaster, as the last of the 301 victims were buried.
Ramazan Dogru, general manager of Soma Coal Mining Company, and Chief Executive Can Gurkan, the son of company owner Alp Gurkan, were among those arrested.
The arrests came after twenty-six people were detained and questioned. The remaining suspects were released, but could face prosecution later.
An initial report on the possible causes of the accident, cited by prosecutor Bekir Sahiner, indicated that the fire could have been triggered by coal heating up after making contact with the air.
The disaster was the deadliest mining incident in Turkey's history, surpassing the death toll of a firedamp explosion that killed 263 miners in Zonguldak in 1992.
The disaster has sparked protests across Turkey, directed at mine owners accused of ignoring safety for profit, and at Prime Minister Tayyip Erdogan's government, seen as too close to industry bosses and insensitive in its response.