Harare: An explosion rocked a stadium where Zimbabwe's president was addressing a campaign rally on Saturday, state media reported, saying he was not injured and had been evacuated from the scene.

President Emmerson Mnangagwa was safely at a state house in the city of Bulawayo, where he had been speaking ahead of next month's election, the Zimbabwe Herald reported.

Witnesses told The Associated Press that the blast occurred as Mnangagwa had just finished addressing the crowd and was leaving the podium.

The explosion was close to the VIP tent, they said. Several people appeared to be injured, and footage showed medical staff rushing to the scene.

State television immediately cut its broadcast.

The explosion came just hours after a similar attack in Ethiopia, where a blast killed at least one person and injured scores just after the new prime minister addressed a huge rally in the capital.

Presidential spokesman George Charamba told The Zimbabwe Herald that investigations were underway, and pointed out that there have been "multiple attempts" on Mnangagwa's life over the years.

Mnangagwa took power in November after his former ally, longtime leader Robert Mugabe, stepped down under military pressure.

The July 30 election will be the first without Mugabe in the southern African nation since independence in 1980.

Bulawayo, Zimbabwe's second-largest city, is traditionally an opposition stronghold.