A coalition of labor unions claiming to represent 330,000 Turkish workers went on strike and held demonstrations on Monday to protest Prime Minister Recep Tayyip Erdogan, according to CBS News. Two large labor confederations, KESK and DISK, joined with smaller unions representing professionals such as doctors, dentists and engineers. Demonstrators gathered in Kizilay Square in Ankara, Turkey’s capital, “about 50 meters away from riot police and a line of trucks.” Union-backed demonstrators in Istanbul, hoping to reach Taksim Square, were stopped by police who had blocked off the area.

Monday marked the second strike since the protests began in Turkey two weeks ago. Labor leader Kivanc Eli Acik said that after the first strike,

Rather than stopping the violence, the excessive police violence and intervention is going much, much bigger. So this is the second warning, the second strong message to the government.

Deputy Prime Minister Bulant Alinc said Monday that Turkey might have to resort to the armed forces to quell the disturbance.

Our police, our security forces are doing their jobs. If it’s not enough, then the gendarmes will do their jobs. If that’s not enough … we could even use elements of the Turkish Armed Forces.

Four protestors and one police officer have been killed since the protests began.