More than 300 taken from Nigeria school in one of worst mass abductions

Officials have said the school had not followed warnings to close before the attack

More than 300 children and staff are thought to have been abducted from a Catholic school in Nigeria this week, one of the worst mass kidnappings ever recorded there.

The Christian Association of Nigeria (CAN) said on Saturday it had raised its estimate of those taken from St Mary's School in Niger state on Friday to 315 from an earlier estimate of 227 following a "verification exercise".

"This now makes it 303 students (and) ... 12 teachers, bringing the total number of abducted persons to 315," it said in a statement, adding the new figure included 88 students who had been captured as they tried to escape.

The kidnapping comes amid a surge of attacks by armed groups and Islamist insurgents in Nigeria, which has been under heightened scrutiny since US President Donald Trump threatened military action this month over the treatment of Christians.

If confirmed, the revised number of people taken at the school would exceed the 276 schoolgirls abducted by Boko Haram militants in Chibok in 2014.

The Niger state government said on Friday the school had ignored an instruction that boarding schools should be closed because of intelligence indicating a high chance of attacks.

But Reverend Bulus Dauwa Yohanna, the CAN chairman in Niger, said no such warning had been issued after travelling to the school on Friday night.

"We are working with the government and security agencies to see that our children are rescued and brought back safely," he said in the CAN statement.

The central government has ordered nearly 50 federal colleges to close and public schools in some states have also been shut.

Friday's mass kidnapping was the third such incident in Nigeria this week alone.

On Monday, 25 schoolgirls were taken from a boarding school in Kebbi state, while on Wednesday 38 worshippers were taken by gunmen in an attack on a church in Kwara state.

A senior US State Department official said on Thursday the US was considering actions such as sanctions and Pentagon engagement on counterterrorism as part of a plan to compel the Nigerian government to better protect Christian communities and religious freedom.

Nigeria says claims that Christians face persecution misrepresent a complex security situation and do not take into account efforts to safeguard religious freedom.