300 Turkish coal miners are protesting working conditions by barricading themselves inside a 170-meter deep mine in the province of Zonguldak, Turkey's Dogan news agency reports.
The miners, members of the Turkish Hard Coal Authority (TTK), are demanding improved working conditions and safety measures.
Night shift workers began the strike and were joined by day shift miners early Friday morning.
Miners cite the late arrival of ambulances as one example of poor safety measures. A worker who spoke with Dogan said that the miners "had been exposed to psychological pressure for a year" and "reached the end of their rope" after a worker suffered a heart attack and an ambulance took 35 minutes to arrive.
The miners say they will continue the protest until their demands are met.
Zonguldak – Turkey's coal capital – has a grim history of coal mining accident.
In September two miners narrowly escaped death after shaft walls collapsed – they happened to be standing underneath one segment of ceiling that didn't crumble.
Earlier this year a gas leak killed eight miners.
In 2010, 30 miners died after an explosion trapped them 540 meters underground. It's believed they died from carbon monoxide poisoning.
The country's worst mine disaster in 1992 killed 270 workers in Zonguldak.
According to Hurriyet Daily, Turkey has the worst safety record in Europe in terms of mining accidents and explosions, and the third-worst in the world: A total of 2,554 miners died between 1991 and 2008.