ISTANBUL (AP) — Police used tear gas and water cannon on Saturday to push back crowds of protesters who defied a warning by Turkey’s prime minister and gathered in Istanbul and Ankara on the anniversary of last year’s nationwide anti-government demonstrations.

Riot police fired tear gas on hundreds of protesters on a main pedestrian street leading to Istanbul’s main square, Taksim, following a stand-off with police. Clashes also erupted in the capital Ankara, where police used water cannons against a group of stone-throwing protesters.