Turkish police detained 18 people, including mining company executives and personnel, as part of an investigation into last week’s mine disaster, CNN Turk and other broadcasters reported on Sunday.

The rescue operation at the coal mine, in the western town of Soma, ended on Saturday after the bodies of the last two workers were carried out, bringing the death toll in Turkey’s worst industrial accident to 301.

The accident happened on Tuesday when a fire sent deadly carbon monoxide coursing through the mine, operated by Soma Madencilik.

Local prosecutors are questioning the company employees at a Soma court house, a police official told Reuters.

He was unable to give Reuters news agency any further details.

The disaster caused protests across Turkey, aimed at mine owners accused of ignoring safety for profit, and at Prime Minister Tayyip Erdogan’s government, seen as too close to industry bosses.

On Saturday, police put the town of Soma on virtual lockdown,setting up checkpoints and detaining dozens of people to enforce a ban on protests.

Security in the town remained tight on Sunday.

Al Arabiya