Nigeria’s former military dictator and main opposition presidential candidate on Wednesday launched his campaign telling supporters to “lynch” anybody who attempted to rig the April vote.

Retired General Muhammadu Buhari, a reputed stern and anti-corruption figure, told thousands of supporters to guard their ballots.

“You should never leave polling centres until votes are counted and the winner declared and you should lynch anybody that tries to tinker with the votes,” Buhari told a large crowd of supporters in his local hausa dialect.

Past elections in Africa’s most populous nation have been marred by violence and vote rigging.

“Resist any attempt to rig the elections,” he said.

Buhari, who ruled Nigeria with an iron fist for about 18 months two-and-half decades ago is making his third attempt to return to office as civilian leader.

Running on the ticket of the Congress for Progressive Change (CPC), Buhari, a Muslim northerner, is facing up against President Goodluck Jonathan, a Christian from the south.

Many northern political leaders are enraged at the choice of Jonathan as the ruling Peoples Democratic Party (PDP) candidate, a move which upset an internal party arrangement to rotate power between the north and the south.

They had opposed his candidacy on grounds that his predecessor Umaru Yar’Adua died before he completed the term allotted to their region.

Despite the tight security at the venue, an AFP correspondent saw some of Buhari’s supporters tearing down two of Jonathan’s campaign billboards plastered at the rally venue, a 15,000-capacity Murtala Mohammed square in Kaduna, the historical political headquarters of northern region.

Jonathan is favoured to win the April election in Africa’s largest oil producer.

But observers say the lanky and bespectacled Buhari, 68, could upstage Jonathan if he went into an alliance with another strong opposition party.

Talks between CPC and another leading opposition Action Congress of Nigeria (ACN) party stalled after as the two groups failed to agree on key issues, including choice of a joint presidential candidate.

Buhari’s draws much of his support from the mainly Muslim north.

Ethnic, religious and regional factors are likely to play key roles in the April ballots to chose a president, legislators and state governors.

Security was tight in Kaduna, a northern state which has in the past witnessed several bloody clashes, and also neighbours Plateau State, the central region beset by sectarian violence.

Some 25,000 policemen were deployed in the state’s capital city, with 17,000 around the rally venue and the rest elsewhere in the city including the offices of the ruling PDP.

-AFP