Looters raided shops and burned-out cars blocked roads in South Africa's capital on Wednesday, the third day of violence triggered by the ruling party's choice of a mayoral candidate for local polls.
Police said rioters were targeting foreigners' shops as public anger mounted over economic hardships in the build-up to August 3 elections likely to become a referendum on President Jacob Zuma's leadership.
Residents of Pretoria's townships started setting cars and buses on fire Monday night after the ruling African National Congress' (ANC) named a candidate in the Tshwane municipality where the capital city is located, overruling the choice of regional branches.
Violence flared again on Tuesday night and continued in parts of the capital on Wednesday, Tshwane Metro police spokesman Console Tleane said.
"There is calm in some hot spots, (but) the navigation of the streets is difficult because of the rubble and the debris," he told eNCA television.
Protesters were continuing to clash with police and "a disproportionate part of the looting was taking place at shops owned by foreign nationals," he added.
Foreigners, many of them from other African countries, last suffered a wave of attacks in April last year, by crowds blaming them for taking jobs and business.
Analysts warned of more unrest in the commercial hub of Gauteng province, which includes Pretoria and Johannesburg.
"Intra-ANC, election-related, factional violence is being ignored by markets trading on external factors, but is worrying," London-based Nomura emerging markets analyst Peter Attard Montalto said in a note.
The mayoral dispute flared over the weekend after an ANC member was shot dead on Sunday as party factions met to decide on a candidate for mayor of Pretoria's Tshwane municipality.
The ANC leadership then named senior party member and former cabinet minister Thoko Didiza as its candidate for Tshwane, overriding regional branch members and refusing to back down as the violence mounted.
The ANC said it picked the candidate as a compromise between two rival factions in Tshwane. But critics say the decision by the party, which has been in power since the end of white-minority rule in 1994, showed that it is losing its touch in areas - including Pretoria - where it was once unassailable.
Zuma survived impeachment in April after the Constitutional Court ruled that he breached the constitution by ignoring an order by the anti-graft watchdog to repay some of the $16 million in state funds spent renovating his home.
"Ahead of the August elections, disgruntled ANC supporters in Gauteng will be motivated by the Pretoria riots to stage further protests to demonstrate the unpopular ANC leadership's decisions," Robert Besseling, head of the EXX Africa business risk intelligence group said in a note.