At least 47 people, most of them students, were killed Monday when a bomb ripped through a school assembly in Nigeria's northeastern town of Potiskum, police said.

The attack took place at a boys' science and technical school in Yobe State, a territory that has seen numerous attacks by Boko Haram extremists.

"There was an explosion detonated by a suicide bomber," national police spokesman Emmanuel Ojukwu told AFP news agency, adding that the Islamist group was likely to blame.

"We have 47 dead and 79 injured," he added.

Mariam Ibrahim, a teacher at the Government Science Secondary School (GSS) in Potiskum, told Reuters news agency the bomb went off as she was arriving and students were having their usual morning briefing.

Potiskum resident Aliyu Abubakar said he heard the explosion when he was dropping off his two sons at a nearby Islamic college. "One of my sons fell down, I came out, dragged him in and we drove off back home," he said.

"There are some (others) that are critically injured and I am sure the death toll will rise," another teacher said, asking to remain anonymous.

Soldiers chased away

Soldiers rushed to the scene of the blast, but they were chased away with stones and calls by people angry at the military's inability to halt an Islamist insurgency that has killed thousands and driven hundreds of thousands from their homes.

Last week, suspected Boko Haram fighters attacked a religious procession of Shiite Muslims in the same city, killing 30 people.

Boko Haram, whose name means "Western education is sinful" in the local Hausa language, has targeted schools, abducted students and killed thousands in its campaign to carve out an Islamist state.

The group has increased attacks and bombings since the government announced it had brokered a ceasefire on October 17.

Boko Haram leader Abubakar Shekau has denied negotiating a truce.

(FRANCE 24 with AFP, REUTERS, AP)