Gunmen attacked a barge belonging to an oil services company off the coast of Nigeria on Saturday, kidnapping four foreigners and killing two Nigerian sailors, the navy said.

"Four expatriates are reported to have been kidnapped from the vessel. Two sailors were killed," navy spokesman Commodore Kabir Aliyu said, adding that the nationality of those abducted had yet to be ascertained.

Nigeria's military said Wednesday that two suspected Boko Haram Islamists who were trying to smuggle heavy weapons into the country were killed by troops during a shootout on the border with Chad.

The alleged insurgents were caught carrying rocket-propelled grenades, Kalashnikov rifles as well as other assorted ammunition and weaponry, Sagir Musa, a military spokesman in the northeastern town of Maiduguri told Agence France Presse.

Suicide blasts at two police stations in northwestern Nigeria's city of Sokoto on Monday left one officer and a civilian dead, while injuring 30 others, a Red Cross official said.

"A policeman and woman were killed in the bombings. Thirty people were injured," said the official who asked for anonymity and confirmed that both blasts were suicide bombings. The two bombers also died, the official added.

Motorcycle gunmen opened fire on the car of a Nigerian air force officer on Sunday, killing the driver and an aide, while two other people were killed in a nearby neighborhood, authorities said.

It was not clear who was behind the attacks in the city of Kano, the largest in Nigeria's mainly Muslim north, but they resembled similar killings in the past blamed on Islamist militant group Boko Haram.

Nigerian soldiers have arrested 26 alleged members of Islamist group Boko Haram and killed two others in a raid after an attack that left two Indian nationals dead, a statement said Saturday.

Separately on Friday, a military patrol vehicle was attacked in the northeastern city of Maiduguri, with two alleged Boko Haram members killed and two soldiers wounded in a resulting clash, and 25 suspects arrested.

An explosion rocked central Nigeria's city of Jos on Tuesday, with an official saying a bomb detonated outside a government building while residents reported heavy weapons fire from a lone attacker.

"There was an explosion this morning... in the Bukuru area of Jos South. The bomb was intended to blow up the secretariat of Jos South local government," said the Plateau state governor's spokesman Pam Ayuba.

The Nigerian army said Sunday it plans to raid suspected militant hideouts in several central villages after attacks last weekend claimed by the Islamist Boko Haram sect that killed over 100 people.

"We will conduct operation sweep and search this week in some villages in Plateau state we suspect are hideouts of miscreants and assailants," army spokesman Captain Salihu Mustapha told Agence France Presse, adding that residents had been warned to leave to avoid getting caught up in any violence.

Nigerian Christians on Saturday condemned an attempt on the life of a key Islamic leader the previous day, a suicide bombing that missed its target but killed five bystanders.

The teenage assassin also died in the attack after Friday prayers outside a mosque in Maiduguri, the capital of northeastern Borno state which is a hotbed of the radical Islamist sect Boko Haram.

A suicide bomber in north Nigeria tried to assassinate a key Islamic leader outside his mosque after Friday prayers but missed his target and killed five others, police said.

The attempt to kill Umar Garbai el-Kanemi, who carries the title of Shehu of northeastern Borno state, was likely to be blamed on Islamist group Boko Haram, who have launched a wave of attacks in Nigeria.

More than 100 people who went to scoop up oil from an overturned oil tanker were burned to death on Thursday after the vehicle caught fire, the information commissioner in Nigeria's southern Rivers state said.

"More than 100 people were killed in the inferno from the petrol tanker, while around 50 with severe burns have been hospitalized," Ibim Semenitari told Agence France Presse.