HARARE --Zimbabwean police said Sunday 49 people have so far been confirmed as injured in Saturday's rally blast in the second city of Bulawayo.

"So far the number of people injured is 49 and they are currently receiving treatment. However, we expect the number to rise as some victims might come forward during the course of the day," police spokesperson Charity Charamba told a press conference.

She said comprehensive investigations are underway on the blast which occurred shortly after Zimbabwean President Emmerson Mnangagwa had finished addressing the rally.

Mnangagwa escaped unhurt but several senior government officials were injured who include vice president Kembo Mohadi and ZANU-PF chairperson and cabinet minister Oppah Muchinguri.

Mnangagwa, who has survived numerous attempts on his life, has described the blast as a "senseless act of violence and cowardice".

He blames the incident on forces bent on derailing progress being made by his administration since he assumed power following the resignation of former president Robert Mugabe last November.

He said the incident will not stop him from forging ahead with his campaigning ahead of general elections scheduled for July 30.

Zimbabwe's election campaign has been generally peaceful until the rally blast.

Zimbabwe's polls will be held in the presence of Western observers for the first time since 2002.

A total of 23 presidential candidates have registered to contest the poll.