The violence erupted earlier this week in slum areas of the capital after the recent murders of at least seven people, whose body parts such as ears, hearts and penises had been removed.
Hundreds of residents stoned houses and shops owned by foreign nationals, with some foreigners seeking refuge at police stations as looters took food, drinks, refrigerators and other electrical appliances.
"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.
Minister of Home Affairs Davies Mwila blamed the riots on false allegations that a suspected ritual killer of foreign nationality had been released from police custody.
Several thousand refugees from Rwanda live in Lusaka.
They run many of the shops in the affected parts of the city, and residents have accused them of using the body parts for witchcraft.