Families of abducted Nigerian schoolgirls have expressed grief and disappointment after the authorities retracted a statement that some of the missing girls had been rescued by the military.

Police said on Wednesday that 111 girls from the government Girls Science and Technical College, a state-run boarding school in Dapchi, in Yobe state, were unaccounted for after an attack suspected to be by the Boko Haram group on Monday night.

The Yobe state government issued a statement on Thursday that the girls were rescued but retracted it within 24 hours, saying the information was "not credible".

Zainab, a 14-year-old schoolgirl, was one of the students abducted along with others; her mother could not bear the news that her daughter was not coming home yet.

"The mother is in hospital. She fainted on hearing that her daughter wasn't found. The grief is too much for her," Sule Ali, Zainab's father, told Al Jazeera.

Witnesses told Al Jazeera that some of the attackers were dressed in military uniforms as they passed through the school gates. Many of the students who were alerted by gunshots, were able to scale the school's perimeter fence and escape. Some of them said they saw dozens of their schoolmates being led into a waiting truck.

"We heard gunshots. There was chaos everywhere," Hadiza Makinta, an escapee, told Al Jazeera.

"Four of us sisters started running together. She fell, and I fell down too. But someone picked me up. That was the last time I saw her. She was taken," Makinta said referring to her eldest sister.

Residents hope the tragedy won't be as drawn-out as the 2014 Chibok incident where more than 270 girls were kidnapped from their school. More than a third of them are yet to be found.

More than 20,000 people have been killed and two million others forced to flee their homes in northeastern Nigeria since Boko Haram launched a campaign in 2009 aimed at forming a breakaway state.

Over the years, the armed group has kidnapped thousands of adults and children.

Ali still hopes to hear good news about the return of Zainab.