* Jonathan's handling of bombs sparks propaganda war
* Northern opponents unite against president
* Row risks overshadowing election campaign
(Adds comments from president's campaign manager)
LAGOS, Oct 7 (Reuters) - Less than a month after launching his election campaign in a blaze of optimism, Nigerian President Goodluck Jonathan has found himself fighting a potentially damaging propaganda war over last week's car bombs.
Jonathan's assertion that rebels from his Niger Delta home region were not wholly responsible for twin bomb attacks near an independence day parade last Friday has laid him open to a barrage of criticism from rivals who accuse him of partisanship.
As the first head of state from the southern Niger Delta, Jonathan already faced a tough battle convincing some in the ruling party to back his election bid and jettison a gentleman's agreement that means the next president should be a northerner.
The unwritten pact in the People's Democratic Party (PDP) is meant to prevent tribalism and regional rivalries becoming a factor in federal politics by ensuring power rotates every two terms between north and south. [ID:nLDE68H047]
The Movement for the Emancipation of the Niger Delta (MEND) claimed last Friday's blasts in statements emailed to media.
But Jonathan's assertion that the bombs had nothing to do with the Niger Delta and that MEND's name was used as a cover, along with suggestions from the authorities that associates of his main rival, former military ruler Ibrahim Babangida, may be involved have infuriated and united his northern opponents.
"The man ... who only a few weeks ago moved us with lofty words of hope and a vision of transformation, shot himself in the foot and then put the bloody foot in his mouth," wrote Tolu Ogunlesi, a journalist on Nigeria's Next newspaper.
"The incident momentarily stripped him of his presidential garb and wrapped him in the gaudy garments of a tribal chieftain," he said.
Babangida and three other northerners running against Jonathan issued a joint statement accusing him of using the blasts as a pretext to intimidate his opponents. Another group of northern politicians called on him to resign. [ID:nLDE6941BB]
Their fury was piqued by the brief detention of Babangida's campaign director Raymond Dokpesi for questioning over the blasts by the secret service on Monday. [ID:nN05292012]
The presidency said the investigations were being carried out on the back of U.S. and British as well as Nigerian intelligence and that anybody could be invited for questioning.
Jonathan's campaign director struck back on Thursday.
"The president did not say that it is not MEND, but what he said is that it is not only MEND that was responsible," Sarki Tafida told a news conference in Abuja.
"The provocative comments of some of our yesterday's men laced with demeaning ethnic chauvinism suggests they do not mind if Nigeria explodes if they don't acquire power at all cost."
Jonathan started his election campaign almost three weeks ago on a high, having unveiled plans to privatise the power sector and end chronic power shortages, better manage the country's oil savings and fight criminality. [ID:nLDE68H06J]
He pledged a new era of leadership "uncontaminated by the prejudices of the past" and his campaign team hoped the momentum would carry him into the primaries, originally due this month.
But the timetable was revised to allow the electoral authorities to overhaul voter lists, handing his northern rivals more time to steel themselves.
The bomb blasts were another blow to his strategy.
Beneath all the finger pointing and rhetoric, none of Nigeria's political class emerge well from the episode.
Jonathan was vice president when Henry Okah, a senior militant figure charged in Johannesburg this week with conspiring to carry out the attacks, had treason and gun-running charges against him dropped under an amnesty deal.
Aliyu Gusau, another northern presidential candidate who has criticised Jonathan, was the country's national security adviser until three weeks ago. Security experts say Friday's attacks would have been months in the planning.
Babangida's opponents say his assertion that Jonathan does not have a firm grip on national security is rich coming from a man largely remembered for his 1993 cancellation of an election generally regarded as fair which led to civil unrest and a bloody crackdown by the security forces.
"Politicians in Nigeria are very good at arguing with each other," said Antony Goldman, a Nigeria expert and head of London-based PM Consulting.
"But the temptation to try to extract political advantage from a national emergency reveals the deeper issue that ten years after the end of military rule, the whole political class struggles to make itself relevant to the people."
The propaganda war will rumble on and it is unclear what impact, if any, it will have on the candidates' fortunes. But it bodes ill for any hopes that the elections will be based on real issues rather than scaremongering and personality clashes.
"The bomb blast is a shame because it could have been prevented, but you know in Nigeria we don't pay attention to the things that really matter," said Kehinde Osho, 24, a graphic artist in the commercial hub Lagos.
"Elections are next year and the voters are not even registered yet. We are fighting a lost battle -- we won't have a credible election with this kind of preparation." (For more Reuters Africa coverage and to have your say on the top issues, visit: af.reuters.com/ ) (Additional reporting by Yinka Ibukun in Lagos; Editing by Diana Abdallah)