Zimbabwe's top court dismisses an opposition bid to have presidential election results annulled over alleged rigging in favour of Robert Mugabe's successor, Emmerson Mnangagwa.

Zimbabwe President Emmerson Mnangagwa escapes unhurt after an explosion rocked a stadium where he was addressing a political rally on Saturday, a month before the country is due to hold its presidential elections.

Emmerson Mnangagwa is sworn in as President of Zimbabwe in front of thousands of cheering supporters at Harare's national stadium, bringing the final curtain down on the 37-year rule of Robert Mugabe.

Incoming Zimbabwe leader Emmerson Mnangagwa assures former president Robert Mugabe he and his family will be safe in the country when the two men spoke for the first time since Mnangagwa returned home this week, state media says.