President Jacob Zuma on Thursday vowed his government would do everything it can to help the families of 80 South Africans believed killed in last week's church collapse in Nigeria.

Facing allegations that the South African government's response to the tragedy was tardy and inadequate, Zuma said he had appointed a ministerial task force to respond.

State governors from Nigerian President Goodluck Jonathan's ruling party on Wednesday said they would back his bid to run for a second term, in a strong indication that he will stand for re-election.

Jonathan has not yet announced whether he will seek office for another four years and the issue has divided his Peoples Democratic Party (PDP), leading to the defection of a number of governors and lawmakers to the main opposition.

At least 13 people were killed and 34 injured on Wednesday as a gunbattle broke out between police and suspected Boko Haram suicide bombers in Nigeria's second city of Kano, police said.

Kano State police commissioner Adelere Shinaba said the gunmen, whom he described as "insurgents", ran into the Federal College of Education after exchanging fire with police outside the grounds.

Suspected Boko Haram gunmen opened fire on a military convoy at the weekend in central Nigeria's Kogi state, injuring four soldiers, a senior military source said Tuesday.

Nigerian senators said Tuesday they will meet with President Goodluck Jonathan to press him to declare "total war" on Boko Haram, in a sign of frustration and concern over worsening security.

The upper house lawmakers will urge Jonathan "to declare total war on Boko Haram in the northeastern part of Nigeria and wherever else in Nigeria they may be".

Twelve Nigerian soldiers were on Tuesday sentenced to death for mutiny after shots were fired at their commanding officer in the restive northeast city of Maiduguri earlier this year.

A nine-member military tribunal, sitting in Abuja, convicted the soldiers following the incident on May 14 when shots were fired at the commanding officer of the Nigerian Army's 7th Division, which is tasked with fighting Boko Haram insurgents.

Nigeria's military on Monday appeared to rule out sabotage after an airforce jet disappeared while on operations in the insurgency-hit northeast.

Air Marshal Adesola Amosu, Nigeria's chief of air staff, suggested enemy fire may not be to blame, telling reporters that the military was "in full control of the airspace" in the region.

Rescue workers have pulled three more bodies from a collapsed guesthouse at a megachurch in Nigeria's financial capital Lagos, raising the death toll to 45, emergency services said on Monday.

Ibrahim Farinloye, southwest coordinator for the National Emergency Management Agency (NEMA), told AFP by text message that 45 bodies had now been removed from the rubble on the sprawling campus of the Synagogue Church of All Nations (SCOAN) in the Ikotun of Lagos.

Forty people have now died as a result of a building collapse at the megachurch of one of Nigeria's most famous preachers and televangelists, the country's main rescue body said on Sunday.

"It's now 40 dead," Ibrahim Farinloye, southwest coordinator of the National Emergency Management Agency (NEMA), told AFP by text message.

A Nigerian Air Force jet has been missing for two days after disappearing in the country's far northeast, where troops are fighting Boko Haram insurgents, the military said on Sunday.

The Alpha Jet, with two pilots on board, left its base in Yola, Adamawa state, on what was described as a "routine operational mission" at about 10:45 am (0945 GMT) on Friday and had been expected back by midday the same day.