Turkish police have fired tear gas and water cannons to disperse hundreds of protesters on an Istanbul street calling for an end to curfews in the southeast, where the military has ramped up operations against Kurdish militants.

Protesters and stunned tourists used lemons and soft drinks to neutralize the effects of the tear gas on Sunday as they poured out of Istiklal Street, a bustling commercial artery. Riot police chased protesters down small side streets and made arrests as helicopters flew overhead.

Witnesses said stone-throwing teens clashed with police in the adjacent neighborhood of Tarlabasi, a hub for Kurdish immigrants from southeastern Turkey.

Turkey has stepped up security operations in the mainly Kurdish towns of Silope and Cizre. About 10,000 troops have been deployed, according to local media.