Dozens of people have been detained in Turkey's largest city and police blocked the central Taksim square as the LGBTQ+ community attempted to hold a Pride parade.
Turkish activists defied a government ban to hold an annual gay pride march in Istanbul on Sunday.
At least 40 people were arrested during the event, Pride organizers said.
Amnesty International's Turkey office said at least one person suffered head injuries while being detained by police.
The latest arrest come after conservative President Recep Tayyip Erdogan won another presidential term to extend his rule until 2028. During his election campaign, Erdogan said the LGBTQ+ people undermined family values, reiterating his government's disdain for the community. He and his representatives have attempted for years to block the annual Istanbul Pride Parade.
Davut Gül, governor of the Istanbul Province, suggested ahead of the event that he would not allow it to go ahead, citing concerns regarding "threats to family life."
"We don't accept this hate and denial policy," Istanbul LGBTI+ Pride Week said in a statement.
Several events linked to Pride Month, including a picnic and a film screening, were already prohibited.
On Sunday, Istanbul police cordoned off large parts of the inner city before the march got underway to deter the participants from rallying. But hundreds of Pride participants instead rerouted to another part of the city and eventually gathered in Istanbul's upscale Nisantasi neighborhood, waving rainbow flags.
Police in the western Turkish city of Izmir also cracked down on those attending Pride, detaining at least 48 people, according to the organizers.
Turkey's LGBTQ+ community fears more pressure after conservative President Recep Tayyip Erdogan won the May vote. But this year's pride march started and finished earlier than expected without any street clashes or police violence, according to news agency AFP.
Last year, organizers claimed some 400 people were detained amid the festivities, which were also banned.