A Christian organization said Saturday that 315 students and teachers were kidnapped in Nigeria the day before, marking the country’s second mass school abduction in a week and deepening nationwide security concerns.

The early Friday raid on St Mary's school in Niger state in central Nigeria came after gunmen on Monday stormed a secondary school in neighboring Kebbi state, abducting 25 girls.

The Christian Association of Nigeria said the new number came "after a verification exercise" following the early Friday mass kidnapping, and added that "The total number of victims abducted... is now 303 students and 12 teachers".

The number of students kidnapped is almost half of the school's 629 enrolled pupils.

Authorities in the nearby states of Katsina and Plateau have ordered all schools to close as a precautionary measure.

The Niger state government closed many schools and President Bola Tinubu cancelled international engagements, including attending the G-20 summit in Johannesburg, to handle the crisis.

The two abduction operations and an attack on a church in the west of the country, in which two people were killed, have happened since U.S. President Donald Trump threatened military action over what he called the killing of Christians in Nigeria.

Nigeria is still scarred by the kidnapping of nearly 300 girls by Boko Haram terrorists at Chibok in northeastern Borno state more than a decade ago. Some of those girls are still missing.