(VOVworld)- Tensions have mounted in Turkey since Tuesday’s coal mine explosion killed hundreds of people and wounded hundreds more. Clashes took place between police and protesters in Ankara and Istanbul and Turkey's Confederation of Public Workers Unions called for a massive strike on Thursday. Police used tear gas and water cannons to disperse a crowd of about 4,000 protesters in Kizilay Square, Ankara, and thousands of strikers in Istanbul. Earlier, the police applied similar measures to suppress 800 students who marched near the headquarters of the Ministry of Energy and Natural Resources. Protesters accused the government and the mine industry of being irresponsible.Turkish Prime Minister Recep Tayyip Erdogan admitted that the explosion was one of the worst accidents in modern Turkish history and pledged to investigate its cause. Meanwhile, according to Taner Yildiz, Minister of Energy and Natural Resources, 274 workers have been confirmed dead. The  bodies of 196 victims have been handed over to their families.