President Obasanjo is unhappy with rising insecurity

Police chiefs said they were seeking more resources to help tackle the political violence.

Nigerians are worried that local elections later this month could cause many local disputes to flare.

On Sunday, gunmen shot dead the head of the electoral commission in the central state of Kogi.

And a ruling party candidate and his wife were murdered in Kogi state, last week.

'Overwhelmed by criminals'

The attack occurred one day after bandits ambushed the heavily armed convoy of the Benue state governor on a busy road near Abuja, killing two of his bodyguards.

Akume's convoy was attacked

"The spate of killings is absolutely unacceptable. It doesn't matter the motive, whether it is economic by armed robbers, political because an election is coming, or pure criminality because they don't like their face," said President Obasanjo.

The BBC's Sola Odunfa in Lagos says the attacks have spread fear among Nigerians who feel the police are doing very little to counter the killings.

But police spokesman Emmanuela Ighodalo said they were not being overwhelmed by the criminals and that they were succeeding in the fight against the bandits.

"We have many guns in circulation and we are asking members of the public to cooperate fully with the police for us to undertake the task of protecting people and maintaining law and order," he said.

In response to the attacks, state governors in Nigeria have reportedly decided to acquire bullet proof cars to enhance their security.

Our correspondent says the decision may not be popular among ordinary people in Nigeria who are also being attacked.