Police spokesperson Charity Charamba said three more people had died from their injuries.
Charamba said 26 suspects including 18 at the MDC headquarters in Harare were arrested including Shadreck Mashayamombe.
Ten of the MDC officers were in one room and eight in another room.
She dismissed reports that police were no longer interested in interviewing Tendai Biti but said the MDC Alliance leader, Nelson Chamisa, was not on their wanted list.
Charamba said that about 4000 MDC Alliance supporters, some vendors and street kids armed with iron bars, stones and other weapons participated in the riots, and damaged at least 22 shops and eight vehicles.