South Africans loot foreigners stores in fresh xenophobic attacks in Atteridgeville (VIDEO)

At least 20 shops possibly belonging to immigrants were looted in South Africa's capital overnight, police said on Tuesday, but they could not confirm if the attacks had deliberately targeted foreigners.

Anti-immigrant violence has flared sporadically in South Africa against a background of near-record unemployment, with foreigners being accused of taking jobs from locals and getting involved in crime.

Responding to similar incidents in Pretoria at the weekend, Nigeria's foreign ministry said it would summon South Africa's envoy to raise its concerns over "xenophobic attacks" on Nigerians, other Africans and Pakistanis.

South African police said they did not yet know the motive for the latest attacks, and no deaths had been reported.

"There are allegations that these shops belong to foreign nationals," police spokeswoman Brigadier Mathapelo Peters said.

"It is alleged that the community members are saying that these shops were used for drug dealing but that is unconfirmed. We will only be able to start a formal investigation once the shop owners come forward."

The Atteridgeville neighbourhood, where the looting took place, was calm on Tuesday as police cars drove through the streets.

"We are sick and tired of foreigners who are coming to sell drugs and kill our people, we can't let the community go down like this," said an unemployed man in his mid-twenties, who declined to be named.

South Africa, with a population of about 50 million, is home to an estimated 5 million immigrants.

In April 2015, Nigeria recalled its top diplomat in South Africa to discuss anti-immigrant attacks that killed at least seven people and sent hundreds of foreigners fleeing to safety camps, as authorities sent in soldiers to quell unrest in Johannesburg and Durban.

In 2008, at least 67 people were killed in anti-immigrant violence, with thousands of people fleeing to refugee camps.

Reuters