Families grieving

The workers were trapped at a depth of 540 metres when the powerful explosion, triggered by a build-up of methane gas, caused a massive cave-in.

Rescuers initially tried to reach the trapped miners through the main shaft of the mine, but found that the platform used to lower the workers was extensively damaged.

The operation was then shifted to another shaft 2km from the site of the explosion, forcing rescuers to travel that distance through an underground tunnel.

The rescue efforts were then hampered by huge blocks of stone the size of cars that took time to bypass.

News of the deaths triggered scenes of grief among families waiting at the the mine since Monday for news of their loved ones. 

Many broke down in tears in front of television cameras after hearing the minister's announcement.

Inquiry launched

Explosions and cave-ins are common in Turkey, particularly in private mines where respect for safety regulations is often minimal.

Thirteen workers were killed in February when a methane explosion at a mine in northwest Turkey caused a cave-in.

In December, 19 workers died in a collapse also set off by an explosion.

Abdullah Gul, the country's president, ordered an inquiry on Wednesday into those incidents and Monday's blast.

The country's worst mining accident happened in 1992 when 263 workers were killed in a gas explosion, also at a mine in Zonguldak.

According to official statistics, nearly 2,700 workers died in mining accidents since 1955.