More than 100 girls were missing today, police said, two days after a Boko Haram attack on their school in northeast Nigeria that has raised fears of a repeat of the 2014 Chibok kidnapping that shocked the world.

Islamist militants stormed the Government Girls Science Secondary School in Dapchi, Yobe state, on Monday evening. Locals initially said the girls and their teachers fled.

But fears have been growing about the whereabouts of the students.

Around 50 parents and guardians converged on the school today to demand answers, as police said 111 were still missing.

The police commissioner of Yobe state, Abdulmaliki Sumonu told reporters in the state capital, Damaturu, that "815 students returned to the school and were visibly seen, out of 926 in the school".

"The rest are missing. No case of abduction has so far been established," he added.

The length of time since the attack and Boko Haram's use of kidnapping as a weapon during its nearly nine-year insurgency has increased fears of another mass abduction.

The jihadists gained worldwide notoriety in April 2014 when they abducted 276 girls from their school in Chibok, in neighbouring Borno state.

Fifty-seven escaped in the immediate aftermath and since May last year, 107 have either escaped or been released as part of a government-brokered deal.

A total of 112 are still being held.

Abubakar Shehu, whose niece is among those missing from Dapchi, told AFP: "Our girls have been missing for two days and we don't know their whereabouts.

"Although we were told they had run to some villages, we have been to all these villages mentioned without any luck. We are beginning to harbour fears the worst might have happened.

"We have the fear that we are dealing with another Chibok scenario." The state-run boarding school in Dapchi caters for girls aged 11 and above from across Yobe state, which is one of three worst affected by the insurgency.

Inuwa Mohammed, whose 16-year-old daughter, Falmata, is also missing, said it was a confused picture and that parents had been frantically searching surrounding villages.

"Nobody is telling us anything officially," he said. "We still don't know how many of our daughters were recovered and how many are still missing.

"We have been hearing many numbers, between 67 and 94." Yobe's education commissioner, Mohammed Lamin, said the school had been shut and a rollcall of all the girls who have returned was being conducted.

"It is only after the head-count that we will be able to say whether any girls were taken," he said.

Some of the girls had fled to villages up to 30 kilometres (nearly 20 miles) away through the remote bushland, he added.

Nigeria's information minister said he would visit Dapchi tomorrow with the defence and foreign ministers. Boko Haram has seized thousands of women and young girls, as well as men and boys of fighting age during the conflict, which has left at least 20,000 dead since 2009.

Some 300 children were among 500 people abducted from the town of Damasak in November 2014.

Getting accurate information from the remote northeast remains difficult. The army still largely controls access and infrastructure have been devastated by nine years of conflict.

In Chibok, the military initially claimed the students had all been found but was forced to backtrack when parents and the school principal said otherwise.

As the issue gained world attention, spawning the hashtag #BringBackOurGirls, the then president Goodluck Jonathan was increasingly criticised for his lacklustre response.

The mass abduction and Jonathan's handling of it were seen as contributing to his 2015 election defeat to Muhammadu Buhari, who promised to bring the Boko Haram insurgency to an end.

But despite Buhari's repeated claims the group is weakened to the point of defeat, civilians remain vulnerable to suicide attacks and hit-and-run raids in the remote northeast.

Security analysts told AFP yesterday that government ransom payments to secure the release of the Chibok girls could have given the under-pressure group ideas for financing.

"They need money for arms, ammunition, vehicles, to keep their army of fighters moving across the borders," said Amaechi Nwokolo, from the Roman Institute of International Studies.

"They're spending a lot of money on arms and logistics."