Nigerian soldiers blanketed the town of Bama on Wednesday, where residents stayed indoors after coordinated assaults by heavily armed Islamist insurgents killed 55 people.

The military said the brazen raid was carried out by some 200 gunmen from the extremist group Boko Haram, who stormed the town in a convoy of buses and 4x4 trucks, armed with machine guns and rocket-propelled grenades.

A former Nigerian oil minister who was kidnapped at the weekend by gunmen in the northeastern city of Maiduguri, a stronghold of Islamist group Boko Haram, was released on Monday, police said.

"I can confirm that Shettima Ali Monguno has been released today by his abductors," Borno State police chief Abdullahi Yuguda told Agence France Presse.

Thirty-nine people died and 30 were injured in fierce fighting between Christian and Muslim mobs in central Nigeria's Taraba state on Friday, prompting a round-the-clock curfew, police said.

Scores of houses were set ablaze and destroyed during the clashes in the town of Wukari which come amid a surge in religious violence in the west African nation.

Nigeria's former oil minister was kidnapped Friday by gunmen who stormed his vehicle outside a mosque in the restive city of Maiduguri, a stronghold of Islamist group Boko Haram, his family said.

Shettima Ali Monguno, 87, served as Nigeria's oil minister in the 1970s and held the rotating presidency of the Organization of the Petroleum Exporting Countries (OPEC) in 1972.

Human Rights Watch on Wednesday released satellite images showing massive destruction in the Nigerian town of Baga, voicing concern that the military has "tried to cover up" abuses that should be investigated by the International Criminal Court.

The clashes between soldiers and Boko Haram Islamists sparked massive fires that left nearly half the town destroyed.

A Nigerian judge on Tuesday postponed his verdict against an alleged member of the Iranian Revolutionary Guards who is charged with an illegal arms shipment.

Azim Aghajani, who has been held in detention pending the verdict, was in court alongside his alleged Nigerian co-conspirator, Ali Abbas Jega.

Pirates stormed a cargo ship off Nigeria's oil-producing southern coast, kidnapping five foreign sailors and stealing cash, a watchdog and a security source said Monday.

The International Maritime Bureau (IMB) said the April 25 incident was carried out by "14 heavily armed pirates" who boarded the vessel 45 nautical miles off the Nigerian town of Brass.

Caretaker Foreign Minister Adnan Mansour confirmed the death of a Lebanese citizen in Nigeria on Saturday, the state-run National News agency reported.

“Adel Jamil Bejjani was beaten to death by unidentified men during a robbery operation,” he told NNA.

Dozens of people have been killed in fierce fighting between Nigeria's military and suspected Islamists after troops raided an insurgent hideout in the northeast, a government source told Agence France Presse on Monday.

Gun battles broke out in the remote fishing village of Baga on Friday, forcing residents to flee the town that also serves as a small trading centre on the shores of Lake Chad.

French President Francois Hollande welcomed a family of seven back to France early Saturday as they flew into Paris after two months in the hands of Nigeria's Islamist militants.

The Moulin-Fournier family, which includes four boys aged between five and 12, flew in from Cameroon on a French government Falcon jet with Foreign Minister Laurent Fabius.