By Tuesday, police had arrested 297 people in connection with the violence, according to Govindsamy Mariemuthoo, a Johannesburg police spokesman.
Mariemuthoo said hundreds of foreigners had been spending the night in police stations around the region, fleeing from informal settlements as angry locals raze their shacks to the ground.
Thousands of people have been displaced in the violence which first erupted in the Alexandra township on Monday last week before spreading to other areas.
Many South Africans have blamed immigrants for high levels of crime and unemployment.
Despite the president's faith in the police, the country's biggest labour union and the Human Rights Commission said the situation was so serious now that the army needed to be deployed.
"Police are looking at hotspots. It's a reactive kind of policing approach," said Jody Kollapen, chairman of the Human Rights Commission.
"We have to look at whether we should at least be willing to talk about whether the army should be deployed.
"It sounds drastic but we are dealing with a situation that is volatile, that has proven to be highly unpredictable and quite devastating in how it has played out."
'Incidents of violence'
Tuesday saw more violent attacks, although the situation was generally calmer.
Kalay Maistry, Al Jazeera's correspondent, reporting from Reiger Park, said violence occasionally flared up.
"There are sporadic incidents of violence - it's quiet and then a few moments later it erupts again," she reported.
She said the wave of attacks had put Mbeki under pressure.
"A large part of the anger we're seeing from poor South Africans is the direct responsibility of Mbeki and his government because they haven't delivered on employment," she said.
"They've created jobs but the unofficial rate of unemployment is still 40 per cent."
On Monday, mobs rampaged through Reiger Park and several people were set alight by angry residents.
While the official death toll remained at 22, South African media reported another man was killed and several severely assaulted in the Joe Slovo informal settlement.
The Sowetan newspaper also reported that a businessman was killed by a mob who set his house on fire after accusing him of hiring foreign workers.