Boko Haram extremists have returned most of the 110 girls abducted from their Nigeria boarding school a month ago with an ominous warning, witnesses said.

The fighters rolled into Dapchi at around 2am in nine vehicles and the girls were left in the centre of the town.

As terrified residents emerged from their homes, the extremists said “this is a warning to you all”, resident Ba’ana Musa said.

“We did it out of pity. And don’t ever put your daughters in school again,” the extremists said.

Boko Haram means “Western education is forbidden” in the Hausa language.

Nigeria’s information minister said 76 of the 110 schoolgirls had been confirmed freed and indicated that the number would rise as the release was “ongoing”.

“No ransoms were paid,” the minister, Lai Mohammed, said in a statement. The girls were released “through back-channel efforts and with the help of some friends of the country, and it was unconditional”.

Family members were en route to the town on Wednesday.

“When I get there we will do a head count to see if all of them have been released,” said Bashir Manzo, whose 16-year-old daughter was among those kidnapped during the February 19 attack.

Mr Manzo confirmed that his daughter was among those freed.

“As I speak to you there is jubilation in Dapchi,” he said.

The mass abduction and the government response brought back painful memories of the 2014 attack on a boarding school in Chibok.

Boko Haram militants abducted 276 girls, and about 100 of them have never returned. Some girls were forced to marry their captors, and many had children fathered by the militants.

Residents in Dapchi fled on Wednesday morning upon hearing that Boko Haram vehicles were headed towards the town.

“We fled but, from our hiding, we could see them and surprisingly, we saw our girls getting out of the vehicles,” Umar Hassan said.

“They assembled the girls and talked to them for some few minutes and left without any confrontation,” said another resident, Kachallah Musa.

Their release came a day after an Amnesty International report accused the Nigerian military of failing to heed several warnings of the imminent attack last month. The military has called the report an “outright falsehood”.