Abuja: A bomb went off in a moving vehicle in southern Nigeria`s hydrocarbon capital of Port Harcourt on Thursday, killing two people and triggering fears of a possible first strike by Islamic militants in the South, before police blamed armed robbers for the incident.
Port Harcourt is the capital of Rivers state and hosts a number of oil firm offices.
"Two persons suspected to be armed robbers died when an explosive devise they were carrying went off in Rumuokoro area of Port Harcourt city," Rivers state police commissioner, Mohammed Indabawa, said on phone.
Two people were also injured in the explosion.
The cab on which they were travelling was completely destroyed, a resident said.
He said initially people thought the explosion was caused by a petrol tanker before rumours of a possible strike by Islamic militant group Boko Haram gained ground. Boko Haram is active in the northern part of the country but has not made incursions in the South.
The police said two persons are in hospital under critical condition after the blast but could not say whether they were passengers in the vehicle.
Indabawa said Boko Haram, which has carried out several attacks in northern Nigeria, was not responsible for the explosion.
In the past, other militant groups based in the Niger Delta region had carried out several attacks in Port Harcourt and its environs, but they embraced an amnesty declared by the Nigerian government.
Boko Haram sect had recently bombed newspaper offices in Nigeria, including the influential `Thisday`, killing eight people.
The sect says it has an avowed mission of turning the country into an Islamic state with Sharia rule. But some analysts think there are political motives behind its attacks which also targeted a United Nations building last year.
Nigeria has a population of 180 million, evenly divided among Christians and Muslims, with the former dominant in the South while the latter in the North.