JOHANNESBURG — Violence against immigrants, like some windswept fire, spread across one neighborhood after another here in one of South Africa’s main cities at the weekend, and the police said the mayhem left at least 12 people dead — beaten by mobs, shot, stabbed or burned alive.

Reuters
A policeman used a fire extinguisher to try to save a man who had been set on fire by a mob during anti-immigrant clashes.
The violence continued to rage on Monday, as police fired rubber bullets and made arrests to try to quell the violence in and around Johannesburg, and said the death toll had reached 22, The Associated Press reported.

Thousands of panicked foreigners — many of them Zimbabweans who have fled their own country’s economic collapse — have now deserted their ramshackle dwellings and tin-walled squatter hovels to take refuge in churches and police stations.

On Monday, men wielding clubs and sticks patrolled along the road near one camp — apparently South Africans trying to prevent foreigners from returning, The A.P. said.

This latest outbreak of xenophobia began a week ago in the historic township of Alexandra and has since spread to other areas in and around Johannesburg, including Cleveland, Diepsloot, Hilbrow, Tembisa, Primrose, Ivory Park and Thokoza.

Amid so much violence, the police were spread thin, sending in squads of officers in armored vehicles. “We are using all available resources and will call in reinforcements if the need arises,â€