At least two people have been burned to death in Zambia in riots targeting Rwandan-owned shops over allegations that foreigners were behind a string of ritual killings in Lusaka, police said Wednesday.

"The official number of people who have died from the time the looting started is two. These are the ones who were burned to death on 18 April 2016 in Kanyama," police spokeswoman Charity Chanda said in a statement.

Police were unable to confirm the nationality of the victims.