Five suspected Islamist militants were killed when bombs they were assembling exploded during a shootout with government troops in northern Nigeria, a military commander said Monday.

"I can confirm that five suspected members of Boko Haram were on Saturday night blown to pieces by IEDs (Improvised Explosive Devices)," they were assembling, Colonel Victor Ebhaleme told Agence France Presse.

Suspected members of Islamist group Boko Haram have killed at least eight people, including a policeman, in separate attacks in restive northern Nigeria, police said Friday.

The attacks, which also wounded a policeman, occurred in three different cities, with most of the violence in Maiduguri, the capital of Borno state in Nigeria's northeast where Boko Haram has been based.

The U.S. embassy in Nigeria warned on Wednesday that Islamist group Boko Haram may be planning attacks in the capital Abuja, including against hotels frequented by Westerners.

"The U.S. embassy has received information that Boko Haram may be planning attacks in Abuja, Nigeria, including against hotels frequently visited by Westerners," an emergency message to U.S. citizens on its website said.

Spain said Wednesday that one of its nationals, reportedly a doctor, had gone missing in southern Nigeria and was feared kidnapped.

The disappearance of the man "has all the characteristics of a kidnapping for economic reasons," said Foreign Minister Jose Manuel Garcia-Margallo.

Nigerian Islamists shot dead a seven-year-old girl during a failed attempt to kill her policeman father hours after group members killed three in a separate raid, the army and police said Monday.

Suspected members of Boko Haram, who have repeatedly targeted Nigeria's security services, fired shots into the house of a police sergeant in the northeastern town of Potiskum late Sunday, a police spokesman in Yobe State, Toyin Gbadigisin, told AFP.

A car bombing near a church in northern Nigeria as services were being held on Easter Sunday killed at least 20 people, wounded 30 others and put the country on alert over fears of further attacks.

The explosion, a stark reminder of Christmas Day attacks that left dozens of people dead in Africa's most populous nation and largest oil producer, hit the city of Kaduna, a major cultural and economic center in the north.

Suspected Islamists have killed seven people in a market in northern Nigeria's restive city of Maiduguri in the latest deadly attacks in the region, police said Thursday.

"There was an attack yesterday afternoon at Monday market. Some gunmen suspected to be members of Boko Haram stormed the market around 1330 hours disguised as customers," Borno state police commissioner Bala Hassan told Agence France Presse.

Suspected members of Nigeria's Boko Haram Islamist sect set off a suicide car bomb Saturday during a military raid on their hideout in the northern city of Kano, police said.

The army chief of Kano state Brigadier-General Iliyasu Isa Abba said the explosion was a desperate act aimed at avoiding capture.

A Lebanese businessman who was kidnapped in southern Nigeria's oil-producing Edo State has been released, the director-general of the foreign ministry Haitham Jumaa announced on Friday.

Jumaa said Lebanon’s Charge d’Affaires Shawqi Abu Nassar informed him that Elias Sarkis was set free by his unidentified kidnappers.

A spokesman for Islamist group Boko Haram has ruled out further talks with Nigeria's government after preliminary, indirect contacts aimed at ending scores of deadly attacks.