At least 42 Nigerian school children were missing on Saturday, a day after suspected Islamist militants attacked a school ​in the insurgency-hit northeastern Borno state, a senator for ‌the area said.

Residents said on Friday that armed men abducted an unknown number of students from Mussa Primary and Junior Secondary School in Askira-Uba ​Local Government Area while classes were in session.

Ali Ndume, senator ​for Borno South district, where the school is located, ⁠said in a statement that school authorities informed him that ​32 students were abducted from the school, while another 10 were ​seized from their homes close to the school.

Nigeria's police and military did not immediately respond to a request for comment.

Borno - an area the size of ​Ireland that borders Cameroon, Chad and Niger - remains the epicentre of ​an insurgency by the Boko Haram Islamist militant group that has lasted more ‌than ⁠15 years.

No group has claimed responsibility for Friday's attack, though Boko Haram has carried out similar abductions in the past.

Borno South senatorial district is where Boko Haram kidnapped more than 270 girls ​in the town ​of Chibok in ⁠2014, drawing outrage around the world. The state had not witnessed another school kidnapping since.

Most school ​kidnappings have taken place in the northwest of ​the country, ⁠where armed criminal gangs carry out abductions for ransom.

Separately, U.S. President Donald Trump and his Nigerian counterpart Bola Tinubu said a U.S. ⁠and ​Nigerian military operation had killed Abu-Bilal al-Minuki, the ​second in command of ISIS globally in Borno in the early hours of Saturday.