Nigerian militant group Boko Haram has released most of the schoolgirls it kidnapped in February from the town of Dapchi in Yobe state in the country’s northeastern part, The Guardian reported on Wednesday. The government said 91 of the 110 girls who were abducted have returned so far, and more were expected to be released in the coming days, Sky News reported.

Nigeria’s Information Minister Lai Mohammed said the government had not paid Boko Haram a ransom to secure the girls’ release. “The only condition they gave us is not to release [the girls] to the military but release them in the town of Dapchi without the military presence,” Mohammed told Reuters in Abuja.

Hafsat Abdullahi, whose 16-year-old sister Fatima had been taken away by the militant group, said they were dropped back in Dapchi. “It took us three days to get back to Dapchi,” Fatima told The Guardian. “We were divided into three groups and flown in planes, and taken over rivers in boats.”

Another resident of Dapchi said five girls were reportedly trampled to death as they were being driven away in overcrowded trucks. Mohammed Mdada claimed the militants had apologised to the girls’ parents, and explained to them that they had targeted them because they mistook them to be Christians.

“Boko Haram shook hands with the parents and apologised for abducting them,” Mdada said. “They said that if they knew they were Muslim girls, they wouldn’t have abducted them. They spoke in the Kanuri language and were dressed in black turbans, and they had dressed the girls in cream hijabs.”

Boko Haram had abducted the girls on February 19. It was the biggest mass abduction since the militant group took away more than 250 girls from Chibok town in 2014. Human rights organisation Amnesty International on Monday blamed the Nigerian security forces for failing to act on warnings about a convoy of Boko Haram fighters heading towards Dapchi.