At least 44 of the 129 schoolgirls abducted in the northeastern Nigerian town of Chibok have been released, and have reunited with their parents, according to the Borno state education commissioner.

Education Commissioner Muso Inowu Kubo confirmed the release to Al Jazeera on Friday, not providing further details.

The schoolgirls, aged between 15 and 18, were kidnapped on Monday in a mass abduction blamed on fighters belonging to Boko Haram, a group responsible for widespread attacks that have left hundreds dead in recent months.

The Associated Press news agency reported on Friday that the military was searching for more the 85 girls still missing in the Sambisa Forest, which is known to be a hiding place for Boko Haram fighters.

The military had mistakenly announced that it had freed all the girls from their captors, before redacting their statement.

A town official had responded saying that people angry at the military's false statement and failure to find the abductees were taking the initiative and searching the forest themselves.

Claiming responsibility

The armed group has been on a rampage this week that started with a massive bombing attack on a busy bus station at rush hour on Monday in Abuja, the capital in the centre of the country, that killed at least 75 people.

Boko Haram claimed responsibility for Monday's attack, the deadliest attack ever in the capital, which happened just hours before the girls were kidnapped.

"We are the ones that carried out the attack in Abuja," Boko Haram's leader Abubakar Shekau said in video message obtained by the AFP news agency.

"We are in your city but you don't know where we are."

Shekau, declared a global terrorist by the US which has a $7m bounty on his head, spoke in Arabic and the Hausa

language that is dominant in northern Nigeria.

The 28-minute video made no reference to the abductions from the Government Girls Secondary School but the military, local officials and girls who have escaped have blamed that attack on Boko Haram.

Boko Haram, which says it wants to create an Islamic state in northern Nigeria, is blamed for killing thousands since 2009.

The group's name loosely translates as "Western education is forbidden," and attacks targeting schools and universities have been a prominent feature of the five-year uprising.

More than 1,500 people have been killed in the fighting this year, compared to an estimated 3,600 between 2010 and 2013.

The attacks have undermined the Nigerian government and military claims that they are containing the unrest in the extreme northeast of the country.