ISTANBUL – In a scene reminiscent of the Arab Spring, thousands of people flooded Istanbul’s main square Saturday after a crackdown on an anti-government protest turned city streets into a battlefield clouded by tear gas.

Prime Minister Recep Tayyip Erdogan offered some concessions to demonstrators, but remained largely defiant in the face of the biggest popular challenge to his power in a decade in office, insisting the protests are undemocratic and illegitimate.

Public anger flared among urban and secular Turks after police violently broke up an anti-development sit-in in the landmark Taksim Square, with protests spreading to dozens of other cities as demonstrators denounced what they see as Erdogan’s increasingly authoritarian style.

As protests entered their second day, police fired tear gas and water cannons at angry demonstrators, some of whom threw rocks and bottles on their march toward Taksim. In an area normally abuzz with tourists, stores were shuttered and protesters fled into luxury hotels for shelter. There were hundreds of arrests and injured.

Turkish authorities later removed barricades and allowed thousands of demonstrators into the square in an effort to calm tension. Sounding defiant even as he bowed to protesters and pulled back police, Erdogan promised to stick to the government’s redevelopment plans — which protesters fear will remove one of the few green spaces in the sprawling city.

Erdogan called the protesters a “minority” that was trying to forcefully impose demands and told the opposition that he could easily summon a million people for a government rally.

Interior Minister Muammer Guler said more than 900 people were detained during the protests.