Emmerson Mnangagwa, the president of Zimbabwe, has escaped an apparent assassination attempt during an election campaign rally in the southern city of Bulawayo.

Local media reported that security personnel, several ministers and possibly the vice-president were hurt in the blast in the White City stadium on Saturday.

George Charamba, the president’s spokesman, told the Herald, a local newspaper, that Mnangagwa had not been injured in the attack, which occurred as the 75-year-old head of state had just finished addressing the crowd and was leaving the podium.

“Investigations are under way and more details will be given to the public. There have been multiple attempts on the president’s life over the past five years.”

Footage posted online showed Mnangagwa waving to the crowd, turning to step off the podium and walking into the open-sided VIP tent, where seconds later the explosion occurred. People ducked and screamed and smoke billowed. State television immediately cut its broadcast.

The incident came hours after a blast struck a large rally by supporters of Ethiopia’s prime minister, Abiy Ahmed, in the capital, Addis Ababa, wounding dozens of people. The coming election in Zimbabwe is the latest turning point in the most tumultuous few months in almost four decades of Zimbabwe’s political history.

In November, Robert Mugabe was forced out of power after 37 years, following a peaceful military takeover supported by the vast majority of the 17 million population.

The poll on 30 July pits Zanu-PF, the ruling party, against the Movement for Democratic Change (MDC), the longstanding opposition.

Zanu-PF is led by Mnangagwa, a former vice-president known as “the Crocodile” who took power when Mugabe was ousted. Polls indicate a potentially close race, but one that Zanu-PF should win. Though hard fought, the campaign so far has seen little of the violence associated with previous elections in Zimbabwe.

Past votes have been marked by systematic intimidation of the opposition and fraud, and the US and others have said a credible vote is key to lifting international sanctions.

The EU has deployed election observers in Zimbabwe for the first time in 16 years.

Few experts and analysts, or politicians, have raised the possibility that Mnangagwa might be targeted for assassination. Bulawayo, Zimbabwe’s second-largest city, is traditionally an opposition stronghold but there was no indication of who might be responsible for Saturday’s attack.