ABUJA — Suspected terrorists abducted more than 300 students and teachers in one of the largest mass kidnappings in Nigeria, a Christian group said on Saturday. Some 50 students have managed to escape, it said on Sunday.

The Christian Association of Nigeria said 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 on Saturday, adding that the new figure included 88 students who had been captured as they tried to escape.

On Sunday, it said "50 pupils escaped and have reunited with their parents", adding they escaped between Friday and Saturday.

Alhaji Abubakar Usman, secretary to the Niger state government, had confirmed the incident without giving an exact number of victims, saying the incident had occurred despite earlier intelligence reports indicating heightened security threats in parts of the state.

He said the government, based on the alerts, had ordered the suspension of all construction activities and the temporary closure of all boarding schools in the affected zone. However, St. Mary's School had reopened and resumed academic activities without notifying or seeking clearance from the authorities, "thereby exposing pupils and staff to danger".

Local security agencies have launched a full-scale investigation and search-and-rescue operations to ensure the safe return of the pupils.

Wasiu Abiodun, a spokesman for the Niger state police, told Xinhua News Agency that tactical units of the paramilitary agency, along with military components and other security agencies, have been deployed to the scene. They are combing the nearby forests in an effort to rescue the abducted students.

Xinhua - Agencies