Turkish police on Monday arrested at least 20 people across Istanbul for taking part in last week's deadly anti-government protests, local media reported.
Anti-terror police units, backed by helicopters, sealed off the restive district of Okmeydani where two people were killed during battles between law enforcement officers and protestors, NTV television channel reported.
Turkey has launched an investigation into the deaths of the two men, who were not among the demonstrators.
Ugur Kurt, 30, was shot in the head while attending a funeral. Ayhan Yilmaz, 42, was hit by a hand grenade thrown during the unrest.
Deputy Prime Minister Bulent Arinc said last week that Kurt may have been hit by a stray bullet fired by a police officer.
The Okmeydani district is a Kurdish and Alevi stronghold in Istanbul.
Police also launched similar raids in two other Istanbul districts as part of Monday's crackdown, according to local media.
The deaths, which provoked fresh street battles in the country's largest city, came as tensions mount ahead of the first anniversary of deadly anti-government protests and in the wake of a mine disaster that claimed 301 lives this month.
The renewed anger is a fresh headache for Prime Minister Recep Tayyip Erdogan, who has dominated Turkey's politics for 11 years and has been tipped to run for the presidency in August, after corruption allegations against himself and his inner circle.
Erdogan on Sunday extended his condolences to both victims, days after he branded the demonstrators "terrorists" and defended police for using tear gas and firing live rounds into the air during the unrest.