JOHANNESBURG, South Africa (AP) _ Black workers returned to their jobs in Port Elizabeth on Tuesday after a three-day strike, and police reported riots and strike-related violence left 12 blacks dead, including a policeman.

Sipo Hashe, a leader of the Port Elizabeth strike and boycott that ended Monday, said the action showed the white-minority government ''that the people are suffering.''

The strike was called to protest price hikes for fuel, bus fares and some consumer goods. Gasoline prices were raised by 25 to 40 percent last month.

Police spokesman Col. Gerrie van Rooyen said the situation at Port Elizabeth, on the Indian Ocean, was back to normal and there were no violence incidents in the black townships around the city where some 300,000 blacks live.

''The boycott is over and the buses are full,'' he said.

Tony Gilson, director of the city's Chamber of Commerce, said employers reported normal staff levels. ''By and large, people are back at work,'' he said.

Van Rooyen said incidents of arson, stone-throwing and assaults included the burning of the homes of 11 black policemen and the stoning of 15 police vehicles.

The 12 deaths included victims killed in demonstrations over the weekend in other black townships. Officials said a black policeman was killed in Cradock, where there has been a black boycott of schools for more than a year.

Black policemen and town councilors are seen by militants as agents of the the white minority and are frequent targets of attacks.

Police reported two girls, 3 and 5, whose father is a black councilor at Graaff Reinet, 140 miles northwest of Port Elizabeth, were seriously injured by a gasoline bomb thrown into their home.

Van Rooyen said a 3-year-old black child died Monday when a mob set fire to a house in Port Elizabeth.

''We don't know why they set this house alight,'' he said. ''She was all by heraself at the time.''

More than 220 people, all but one of them black, have been killed in protest violence in the past 13 months.

Business groups and protest organizers said tens of thousands of blacks staged an almost 100 percent boycott of Port Elizabeth shops run by whites, and stayed off the buses that take them from their homes in the townships to the city.

Gilson said most employers decided to dock workers' pay for the days they stayed home but not to fire them or take other disciplinary action.