Zimbabwe's President Emmerson Mnangagwa has told the BBC that he suspects supporters of former first lady Grace Mugabe were behind an attempt on his life.

Two people died and more than 40 were hurt in an explosion near Mr Mnangagwa at a rally in Bulawayo on Saturday.

But exiled former government minister Jonathan Moyo, who was part of the G40 group that backed Mrs Mugabe for the presidency, has said in a tweet that he thinks the blast "smacks of an inside job".

He was referring to an apparent power struggle between Mr Mnangagwa and his deputy, Constantino Chiwenga, the former army chief who forced Robert Mugabe from power last November.

The former minister said that only an independent investigation overseen by the regional body Sadc or the African Union could be trusted to find out who was behind the blast.

Mr Moyo, who once worked as Mr Mugabe's chief spin doctor, said he would be backing opposition MDC Alliance candidate Nelson Chamisa in the elections on 30 July.