Abuja: Two girls were killed and three customs officers seriously wounded in a fresh blast on Monday in Nigeria`s troubled northern city of Maiduguri, an Army general said.
"Three customs officers were seriously injured in the attack while two child vendors -- both of them girls -- were killed in the blast," the commander of the city`s joint task force, general Jack Okechukwu Nwobo, said.
Residents and witnesses put the death toll at about a dozen, however.
"I was about 100 metres from the customs bridge roundabout when the blast happened. It was a crowded area. I saw two vans conveying the dead. From my estimation, not less than 10 people were killed in the blast," a resident near the scene, Sheu Abdulkadir, said.
A local journalist said he saw several dead bodies on the ground after the blast.
"I escaped death by the whiskers. I had just negotiated the roundabout when the blast happened. I saw many lifeless bodies on the ground. I counted at least 12," said the journalist, who did not want to be named.
The exact nature of the blast was not immediately known. Security agents cordoned off the site of the explosion.
Nobody has yet claimed responsibility for the blast, which came less than 24 hours after suspected Islamists of the Boko Haram sect tossed bombs and fired on a crowded beer garden killing at least 25 people.
Amnesty International has condemned the fresh attack, which it labelled bombing.
"Several people were injured in a fresh bombing on Monday, also believed to have been carried out by Boko Haram," the organisation said in a statement.
Sunday`s attack was one of the deadliest in the city in recent months and coincided with the day a special task force of crack troops and other security personnel took control of security operations in the city.
Two men riding motorbikes hurled three bombs into a large beer garden, fired shots and sped away after the shock attack, security sources said from Maiduguri, capital of Borno State.
Boko Haram, which staged a short-lived uprising in 2009, are blamed for almost daily attacks that have targeted mainly police and military personnel, politicians, and community and religious leaders.