ABUJA/MAIDUGIRI, Nigeria: Nigerian security forces are investigating a possible mass kidnapping of villagers in the northeast state of Borno where Boko Haram militants abducted more than 200 schoolgirls two months ago, a security source said on Tuesday.

If confirmed, the latest abduction would fuel public frustration over Abuja’s inability to quell Boko Haram’s five-year campaign to carve out an Islamist state in the mainly Muslim north.

Military officials are looking into reports suspected Islamist insurgents over the weekend raided at least three villages 100 km from the state capital Maiduguri, the source added.

Two residents of the nearby village of Lassa, which wasn’t attacked, told Reuters they spoke to people who reportedly fled as militants killed men and kidnapped “many” women and children.

Nigerian media reported that as many as 91 villagers had been abducted, most of them women and young girls. Reuters was unable to verify these accounts independently. Boko Haram, which has killed thousands in bomb and gun attacks, initially focused on government and security targets, as well as churches and Muslim leaders that rejected its brand of Islam.

But recently it has increasingly targeted civilians, emboldened by global publicity after it kidnapped more than 200 girls from a school in the remote Borno village of Chibok in April.

The abduction of the girls triggered worldwide outcry and sparked a “Bring back our girls” campaign among celebrities, politicians and on social media.

Boko Haram, whose name roughly translates as “Western education is sinful” has killed thousands since 2009. Amnesty International estimates about 1,500 people have been killed in northeast Nigeria in the first three months of this year.

Separately, at least eight people were killed and 20 wounded by an explosion at a college campus in the heart of the northern city of Kano during school hours on Monday.

Politics have bedeviled the issue, with many distracted by upcoming presidential elections in February 2015. The first lady, Patience Jonathan, and some other supporters have claimed the reports of the April abductions of the schoolgirls were fabricated to discredit her husband’s administration.

Last week, a presidential committee investigating the kidnappings stressed that they did in fact happen and clarified the number of students who have been kidnapped. It said there were 395 students at the school, 119 escaped during the siege of the school, another 57 escaped in the first couple of days of their abduction, leaving 219 unaccounted for.

This year, the Boko Haram insurgents have embarked on a two-pronged strategy — bombing in cities and a scorched-earth policy in rural areas where they are devastating villages. Nigeria’s capital, Abuja, the central city of Jos and the northeastern state capital of Maiduguri, the birthplace of Boko Haram, all have been bombed.

On Monday, an explosion at a medical college in the northern city of Kano killed at least eight people and wounded 12, police said. It was the third bomb blast in four months in Kano, Nigeria’s second city.

Also on Saturday, the same day as the latest abductions, scores of Boko Haram fighters attacked four other villages, near Chibok town from which the girls were kidnapped. Witnesses said at least 33 villagers were killed as well as six vigilantes and about two dozen Boko Haram fighters.

The group evolved five years ago from an Islamic sect preaching against the corruption that keeps most Nigerians impoverished despite their country’s oil wealth into a violent movement that wants to enforce Islamic law across Nigeria, though half the country’s 170 million people are Christians.