Zimbabwe's vice president has also said nothing will stop the upcoming election, as police investigate a grenade attack at a campaign rally on Saturday.
Constantino Chiwenga was one of the 49 people injured in the explosion, which targeted President Emmerson Mnangagwa.
Security is now being stepped up ahead of next month's vote.
Al Jazeera's Haru Mutasa reports from Chitungwiza, near the capital Harare.
