Suspected Boko Haram militants have seized a military base in northeastern Nigeria in a series of blistering raids near Lake Chad, sending soldiers and civilians fleeing, witnesses said on Sunday.

Local residents reported that the gunmen killed several people, burnt hundreds of homes and looted scores of businesses in Saturday's attacks, although there was no official death toll.

Suspected Boko Haram gunmen have kidnapped 40 boys and young men in a remote village in northeast Nigerian Borno state on New Year's Eve‎, residents who fled the isolated settlement said on Saturday.

Scores of Boko Haram militants stormed the Malari village around 8:00 pm (1900 GMT) and whisked away the males, aged between 10 and 23, into the nearby Sambisa forest, believed to be one of the Islamists' major bases.

A suicide bomber blew himself up outside an evangelist church in northeast Nigeria on Thursday, injuring several people, witnesses and a rescue worker said.

"There was an explosion outside the ECWA church this morning. A suicide bomber who was restrained from getting into the church blew himself up," said Abubakar Yakubu, who heads the Nigeria Red Cross in Gombe.

Strife-torn northern Nigeria was hit by two deadly attacks on Wednesday, when a female suicide bomber was killed as she tried to enter a military barracks and seven died in a bus explosion.

Soldiers opened fire on the woman when she refused to be searched as she approached the barracks in Bolari, in Gombe state, detonating the explosives belt she was wearing, according to eyewitness accounts.

Two German men have been killed in Nigeria, the foreign ministry in Berlin said Wednesday, as media reported they were engineers shot dead while on a motorcycle trip.

"Unfortunately we can confirm that two German nationals were killed in Nigeria last weekend," a foreign ministry spokesman told AFP. 

Nigeria's main opposition lashed out at the government on Wednesday in a series of New Year's messages as political rhetoric rises six weeks before much anticipated general elections. 

Ex-military ruler Muhammadu Buhari, who is challenging President Goodluck Jonathan in February 14 polls, told "disappointed and angry" voters that in 2015 he would restore Nigeria as "a country that you can be proud of".

A explosion at the main market in northeast Nigeria's Bauchi city killed seven people and injured 25 others in an area repeatedly attacked by Boko Haram, police said Tuesday. 

The blast on Monday evening set much of the market on fire, including an area dominated by women traders, according to the Red Cross. 

A massive explosion at a market in northeast Nigeria's Bauchi city caused "heavy casualties" on Monday, setting the entire area ablaze with rescue workers struggling to reach the scene, the Red Cross said.

A bombing at a bus station in northeast Nigeria killed at least 20 people on Monday, as Boko Haram was blamed for a separate attack in the embattled region.

Violence in the northeast is escalating ahead of Nigeria's February 14 general elections, with many concerned that voting will be impossible in large parts of the region.

Nigeria's military on Friday confirmed a deadly attack by Boko Haram in the northeast village of Gumsuri but said reports of a mass kidnapping needed to be verified.