GERMISTON, South Africa — Aid groups struggled yesterday to feed and shelter thousands of immigrants chased from their homes by attacks on foreigners, while critics said the government must shoulder some of the blame for the eruption of violence.

There was more fighting and unconfirmed reports of new deaths yesterday, but the violence did not appear as widespread as in recent days in the shantytowns around Johannesburg. The official death toll remained at 22.

Many of the attacks have been made by gangs of South Africans armed with rocks, knives, and guns. A tire set on fire with gasoline was put around the neck of one victim.

A Mozambican who has lived in South Africa for 25 years, Abel Massingue, sheltered with other migrants in a littered field next to a police station. He was afraid and in pain after being beaten with hammers Saturday night when he tried to help a friend escape a mob in Germiston, east of Johannesburg.

“It’s terrible here,” Mr. Massingue said. “We have young children here. Some people in here, they have guns, they have weapons.”

Zimbabweans, Malawians, Mozambicans, and others from neighboring countries have been the main targets in the wave of xenophobia. They came to South Africa, the region’s economic hub, looking for work and ended up sharing squatter camps with poor — and increasingly frustrated — South Africans.

Although South Africa is more prosperous than its neighbors, it suffers high unemployment and widespread housing problems, especially among the black majority.

Cabinet ministers and politicians visited some of the worst affected areas yesterday as the government scrambled to repair its international image.

Security Minister Charles Nqakula vowed to increase the number of police patrols to ward off mob attacks, deploy specialized police units, and provide alternative housing for the displaced.

“We are going hard on the situation,” Mr. Nqakula said in Germiston, where a large group of mostly Mozambicans has gathered seeking protection.

The respected Institute for Race Relations put the blame for the violence firmly on the government, saying ineffective policies had “created a tinder box of unmet expectations which exploded.”

The institute cited a long list of factors: a failure to clamp down on violent crime; corruption, inadequate staffing, and low morale among the police; a lack of real job-creating policies; poor delivery of government services, and porous border controls.

It also said heavy-handed police action against immigrants, as evidenced by a raid this year on a Johannesburg church housing hundreds of Zimbabweans, led to the impression among poor South Africans that foreigners are “fair game.”

The institute criticized President Mbeki for what it called “wholly inappropriate and incompetent” diplomacy with Zimbabwe’s autocratic leader, Robert Mugabe. That provided “a lifeline to the ailing Zimbabwe regime” and led to rising numbers of Zimbabweans fleeing their nation’s economic collapse and political repression, the institute said.

The acting secretary-general of the South African Red Cross Society, David Stephens, said he was preparing for a long-term crisis, working with international and local groups and government officials to coordinate aid efforts.