The Islamist group Ansaru on Monday claimed the kidnapping of seven foreigners, including two Lebanese, in a deadly raid on a construction site in northern Nigeria at the weekend.

In an email statement distributed to several journalists, the group said it has "the custody of seven persons, which include Lebanese and their European counterparts working with Setraco," the Lebanese-owned company targeted in the attack.

Gunmen attacked a camp for a construction company in rural northern Nigeria, killing a guard and kidnapping seven foreign workers from Britain, Greece, Italy and Lebanon, authorities said Sunday, in the biggest kidnapping yet in a region under attack by Islamic extremists.

The attack Saturday night happened in Jama're, a town in a rural portion of Bauchi state. There, the gunmen first attacked a local prison, burning two police trucks, Bauchi state police spokesman Hassan Muhammed told The Associated Press.

A bomb explosion targeting soldiers killed at least two people on Friday in the restive northeastern Nigerian city of Maiduguri while houses and shops nearby were burnt, the military said.

The two dead were suspected to be the bombers, according to a statement from Lieutenant Colonel Sagir Musa, though independent confirmation was not immediately available and the military's information is often unreliable.

Two Nigerian journalists and a cleric were granted bail on Thursday after being charged over a controversial radio program on polio vaccines days before deadly attacks on polio clinics.

Gunmen attacked two polio clinics in the northern city of Kano on February 8, killing at least 10 people, after Wazobia FM broadcast a story on claims of forced vaccinations.

Police in Nigeria's Kano state said Monday that Islamist group Boko Haram was behind last month's attack on a key Muslim leader, adding that seven people had been arrested over the incident.

Eight others are wanted in connection with the January 19 attack by a suicide bomber and several gun-wielding accomplices who targeted the convoy of the Emir of Kano, Ado Bayero, killing five but only injuring the emir.

Men armed with knives slit the throats of three South Korean doctors in a pre-dawn attack Sunday in a volatile town in northeastern Nigeria in the latest in a spate of killings of foreigners in recent months, police said.

The attack in Potiskum also came just two days after gunmen killed at least 10 people in horrifying attacks on two Nigerian polio clinics in a new blow to the campaign to wipe out disease, but it was not clear if the incidents were related.

Gunmen killed at least nine people at two Nigerian polio clinics on Friday, with one of the wounded health workers describing a horrifying attack that saw them trapped by fire.

The attacks in the northern city of Kano came after a local cleric denounced polio vaccination campaigns this week and some local radio programs repeated conspiracy theories about the campaigns being a Western plot to harm Muslims.

Iran and Senegal have resumed diplomatic ties severed two years ago after Dakar accused Tehran of supplying weapons to its separatist rebels, the ISNA news agency reported on Thursday.

"The declaration for the restart of political ties between Iran and Senegal was signed by the two foreign ministers on the sidelines" of the ongoing Organization of Islamic Cooperation meeting in Cairo, ISNA reported citing an official statement.

Nigerian Vice President Namadi Sambo said Saturday that his government is ready to consider a ceasefire offer by the extremist Islamist group Boko Haram.

Sambo, speaking during a visit to the northeastern city of Maiduguri -- the Islamists' stronghold -- said "we welcome the ceasefire offer announced recently by the Boko Haram group and we will do everything as a government to see that we achieve a lasting peace in Nigeria."

Nigeria's military on Friday said it killed 17 insurgents in raids on two "terrorist camps" in the embattled northeastern state of Borno, the base of Islamist group Boko Haram.

The military "conducted two special operations supported by Nigerian Airforce helicopter gunship to dislodge Boko Haram terrorist camps," a statement from spokesman Lt. Col. Sagir Musa said.