Turkish police on Sunday detained more than 160 protesters who were trying to hold a May Day rally in defiance of a ban imposed by the governor's office.
AFP images showed riot police clashing with protesters near Istanbul's Taksim Square, pinning some of them forcefully to the ground before rounding them up in a police car.
The Istanbul governor's office said 164 people were held after staging "an unauthorised rally" and refusing to disperse despite police warnings.
An AFP photographer saw around 20 protesters detained near Taksim Square.
"Long live May Day," some of them shouted. "Labour and freedom! Long live May Day."
There are often detentions during the annual May 1 workers' holiday.
Taksim has been a flashpoint on May Day with frequent clashes since 34 people were killed there on May 1, 1977.
A small group led by the Confederation of Turkish Revolutionary Trade Unions attended an officially approved event at Taksim Square.
A usually bustling square lined with cafes and hotels, Taksim was also the epicentre of 2013 anti-government protests.
Protests initially erupted over an attempt to save adjacent Gezi park from demolition at the hands of the government but grew into a broader movement against President Recep Tayyip Erdogan, who was then prime minister.
Critics accuse Erdogan of amassing great power, trampling on human rights and quashing dissent.
An Istanbul court on Monday condemned leading rights activist Osman Kavala to life prison, a ruling that stunned Turkish civil society and prompted criticism from Ankara's Western allies.
He was convicted of financing the 2013 protests.
The court also handed 18-year jail terms to seven other defendants, including architects, urban planners, a film producer and academics.
In the meantime, thousands gathered on Sunday on the Asian side of Istanbul in an authorised rally to celebrate May Day.
"Long live our May Day struggle," they chanted.
Watch latest videos by DH here: