President Jacob Zuma has strongly condemned the violent tensions which have recently broken out between South Africans and immigrants in parts of Gauteng.

His office announced on Friday that he would champion the fight against crime in order to promote safe and stable communities in the country.

"The situation has become more serious in light of current threats of violence and acts of intimidation and destruction of property directed at non-nationals living in South Africa," said the Presidency.

Violent protests broke out in Atteridgeville on Friday morning, with protesters blockading entrances and exits to the township, while an anti-immigrant group prepared to march in the Tshwane city centre.

Zuma also called for residents to exercise restraint.

On Saturday, residents of Pretoria West raided homes they alleged were being used as brothels and drug dens. They called for "pimps" to release prostitutes and send them back home. Two houses were set alight.

On February 11, at least 10 houses allegedly being used for drug dealing and prostitution were set alight in Rosettenville, Johannesburg. Locals claimed Nigerians were behind the criminal activity.

"There are simmering tensions that have been reported in other areas including the dissemination of hate speech and threatening messages via social media," noted the Presidency.

The president has called on people to unite against crime and work with the authorities to bring criminals to book.

Zuma also appealed to citizens not to blame all criminal activities on non-nationals.

"It is wrong to brandish all non-nationals as drug dealers or human traffickers. Let us isolate those who commit such crimes and work with government to have them arrested, without stereotyping and causing harm to innocent people."

The president visited Nyanga in Cape Town two weeks ago, one of the country's leading crime hotspots. He will be visiting other communities as well to obtain a first-hand account of problems faced on the ground with respect to crime, said the Presidency.