A total of 303 schoolchildren and 12 teachers were abducted by gunmen during an attack on St. Mary's School, a Catholic institution in north-central Nigeria's Niger state, the Christian Association of Nigeria said Saturday, updating an earlier tally of 215 schoolchildren.

The tally was changed "after a verification exercise and a final census was carried out," according to a statement issued by the Most. Rev. Bulus Dauwa Yohanna, chairman of the Niger state chapter of CAN, who visited the school Friday.

He said 88 other students "were also captured after they tried to escape" during the attack. The students were both male and female and ranged in age from 10 to 18.

The school kidnapping in Niger state's remote Papiri community happened four days after 25 schoolchildren were seized in similar circumstances in neighboring Kebbi state's Maga town, which is 106 miles away.

No group has yet claimed responsibility for the abductions and authorities have said tactical squads have been deployed alongside local hunters to rescue the children.

Yohanna described as false a claim from the state government that the school had reopened for studies despite an earlier directive for schools in that part of Niger state to close temporarily due to security threats.

"We did not receive any circular. It must be an afterthought and a way to shift blame," he said, calling on families "to remain calm and prayerful."

School kidnappings have come to define insecurity in Africa's most populous nation, and armed gangs often see schools as "strategic" targets to draw more attention.

UNICEF said last year that only 37% of schools across 10 of the conflict-hit states have early warning systems to detect threats.

Niger state has now shut down all schools as a measure to forestall other kidnappings. The decision was in a bid to protect lives and property, Niger Gov. Umar Bago told reporters Saturday after meeting with security officials in Minna.

"It is the decision of stakeholders today to close all schools in Niger state. All schools are closed till further notice. So we have declared Christmas holiday for all schools in Niger state," Bago said.

The kidnappings are happening amid President Donald Trump's claims of targeted killings against Christians in the West African country. Attacks in Nigeria affect both Christians and Muslims. The school attack earlier this week in Kebbi state was in a Muslim-majority town.

The attack also took place as Nigerian National Security Adviser Nuhu Ribadu was visiting the U.S. where he met Secretary of War Pete Hegseth on Friday.