President Goodluck Jonathan on Thursday formally began his campaign for re-election, taking the fight to a key opposition stronghold with a mass rally.

The meeting in Lagos comes as Jonathan’s Peoples Democratic Party (PDP) mounts increasingly personal attacks on his main challenger as well as lingering doubts about whether the vote will even hold.

Nigerians are due to elect a new president on February 14 but there are fears that polling could be ruled out in swathes of the country’s northeast because of sustained Boko Haram violence.

The electoral body in Africa’s leading economy and most populous nation maintains, however, that there were no plans to postpone the vote.

Sirens from convoys of politicians and dignitaries blared in and around the rally venue on Lagos Island from early morning in Lagos and commuter traffic backed up as delegates began arriving.

All roads to the venue were cordoned off and armed soldiers and police searched the crowds, many of them dressed in the PDP colours of red, white and green.