Turkish riot police fired rubber bullets and tear gas to break up a gathering of about 50 members of the LGBT community in Istanbul on Sunday, an AFP correspondent said.
Several hundred police surrounded the city's main Taksim Square to prevent the "Trans Pride" rally taking place during the Muslim holy month of Ramadan.
The crackdown came after police used tear gas, water cannon and rubber bullets on Saturday against people protesting after Islamists attacked fans of British rock group Radiohead for attending an album launch during Ramadan.
A group of about 20 men beat up customers and staff at the Velvet IndieGround music store on Friday night, angry that they were drinking alcohol at the event.
On Saturday, about 500 protesters took to the streets in Istanbul shouting "Shoulder to shoulder against fascism!" and denouncing President Recep Tayyip Erdogan as a "thief" and a "killer".
Turkish authorities have regularly cracked down on anti-government demonstrations since mass protests swept the country in 2013, using tear gas and water cannon against even small gatherings.