(AFP) - Zimbabwe's President Emmerson Mnangagwa said Saturday he narrowly survived an attempt on his life after a blast at a party rally that injured two of his vice-presidents and several party officials.

Fifteen people were injured, three seriously and some lost limbs, in the explosion during an election campaign event in Zimbabwe's second city Bulawayo, according to Health Minister David Parirenyatwa.

Footage circulating on social media showed an explosion and plumes of smoke around the president as he descended stairs from the podium at the city's White City stadium.

Mnangagwa suggested he was the target of the attack, which he said also injured Vice-Presidents Kembo Mohadi and Constantino Chiwenga.

"I am used to these attempts," Mnangagwa told state media, adding that an object "exploded a few inches away from me -- but it is not my time".

ZANU-PF chairwoman and cabinet minister Oppah Muchinguri-Kashiri and Mary Chiwenga, the wife of vice president Chiwenga, were also among those injured, he said, as was deputy parliament speaker Mabel Chinomona.

- 'Senseless act of violence' -

The "blast... has affected my vice-presidents -- especially comrade Mohadi," he added.

Mohadi suffered leg injuries, while Chiwenga had slight bruises to his face, according to the presidential spokesman George Charamba.

State broadcaster ZBC described the blast as "an assassination attempt".

But Mnangagwa insisted that the "country is peaceful" as Zimbabwe prepares to stage its first ever elections not to feature former president Robert Mugabe on July 30.

"Several people were affected by the blast, and I have already been to visit them in the hospital," Mnangagwa wrote on his verified Facebook account describing the attack as a "senseless act of violence".

"The campaign so far has been conducted in a free and peaceful environment, and we will not allow this cowardly act to get in our way as we move towards elections."

State media also reported that the ZANU-PF party secretary in charge of political organisation, Engelbert Rugeje, was injured, as were several security personnel.

Injured ZANU-PF supporters were pictured in a nearby hospital where one man wearing a blood-stained party T-shirt waited for treatment.

According to Charamba, the president was "evacuated successfully" to his official residence in Bulawayo.

- 'People started running' -

Mnangagwa had been in the city to campaign for votes ahead of nationwide elections due on July 30.

"People started running in all directions and then immediately the president's motorcade left at a very high speed. Suddenly soldiers and other security details were all over the place," said an AFP correspondent at the scene.

Bulawayo has long been a bastion of opposition to the ZANU-PF and it was Mnangagwa's first rally in the city.

The polls in five weeks will be the first since Zimbabwe's veteran leader Robert Mugabe resigned following a brief military takeover in November last year after 37 years in power.

The intervention by the army was led by Chiwenga who was then head of the armed forces.

The vote will be a key test for Mnangagwa, 75, who succeeded the 94-year-old autocrat and remains untested at the ballot box.

He has pledged to hold free and fair elections as he seeks to mend international relations and have sanctions against Zimbabwe dropped.

Previous elections in Zimbabwe have been marred by electoral fraud, intimidation and violence, including the killing of scores of opposition supporters in 2008.

Chipo Dendere, a Zimbabwean professor of political science at Amherst College in the US, said the incident would change the tone of the election campaign.

"This is going to make everyone a little bit tense... this is the first time we have seen such a blatant attack," she said blaming divisions inside the ruling ZANU-PF for the attack.

"Whatever internal fissures existed within ZANU-PF before (the coup in) November, those fissures didn’t go away."

Mnangagwa has been accused of involvement in the Gukurahundi massacres of the 1980s that claimed the lives of around 20,000 regime opponents in the country's southwest where Bulawayo is situated.

Twenty-three candidates –- the highest number in the country's history -- will contest the presidential race.

The main competition will be between Mnangagwa and the main opposition Movement for Democratic Change's leader, 40-year-old Nelson Chamisa.

Chamisa condemned the attack, tweeting that "violence must have no place in our politics".

© Agence France-Presse