Nigerian government officials have confirmed that 110 girls are missing after a suspected Boko Haram attack on a school in the northeastern part of the country, TIME reports.

Officials say they believe the kidnapping to be the largest abduction since the militant extremist group kidnapped nearly 300 school girls form Chibok almost 4 years ago.

On Feb. 19, armed insurgents attacked the Government Science and Technical College in Dapchi. The town is located in Yobe state and initially, it was unclear how many girls had been taken.

According to the state’s government, some of the girls had been rescued, but that turned out not to be the case. According to reports, 105 were unaccounted for in the wake of the attack.

Nigeria deployed extra troops tasked with searching for the missing girls the BBC reports.

President Muhammadu Buhari referred to the latest kidnapping as a “national disaster.”