Protesters have hurled petrol bombs at a police station in Bahrain and riot police have responded with teargas and stun grenades.
The violence flared after a funeral march for a man killed in clashes during the Gulf Arab state's Formula One race last week.
Thousands of mourners visited the grave of Salah Abbas Habib, 36, who was found dead on Saturday after disappearing during fighting between protesters and police.
Petrol bombs set the police station's wall alight in the Manama neighbourhood of al Bilad al Qadeem.
The clashes then spilled onto a main road, holding up traffic for up to an hour.
Bahrain has been in turmoil since a pro-democracy uprising erupted last year after successful revolts in Egypt and Tunisia.
Mr Habib was buried by his family in Shakhura village on Monday.
The main opposition party Wefaq says Mr Habib's body showed signs of torture, including multiple fractures and birdshot pellets apparently fired at close range.
The interior ministry has said it will establish what happened to Mr Habib.
Wefaq says his death takes to 81 the number of people killed since the protests began.
That figure includes 35 who died during the initial uprising and more than two months of martial law, among them five security personnel.
The government disputes the cause of death in many cases and says the protesters are hooligans who are trying to kill police.
It says a homemade bomb wounded four policemen this week, and that seven policemen were wounded earlier this month.
The protests escalated before last week's Grand Prix, drawing criticism of Bahrain from some governments, rights groups and media watchdogs.