Forty-four people have been detained during a march for LGBT rights that the governor of Istanbul had banned, Turkey's official news agency said.
Anadolu agency reported that 20 people who "reacted against" the march were among those detained on Sunday.
Ultranationalist and religious groups had threatened the 15th Istanbul LGBTI+ Pride March in the week leading up to it.
Organisers said 27 people who tried to go on with the banned event were detained, including two minors and a Danish activist.
They were released after questioning.
Police set up checkpoints to prevent people from entering Istanbul's main thoroughfare and marching en masse.
Police also used tear gas and plastic bullets on groups of participants.
The governor's office banned Pride for the third year in a row, citing safety and public order grounds.