Armed kidnappers in Nigeria have released 28 of the 120-plus students who were abducted at the beginning of July from the Bethel Baptist High School in the northern town of Damishi.
But Israel Akanji, president of the Baptist Convention, said more than 80 other children are still being held by the gunmen.
Church officials handed the children over to their parents at the school on Sunday.
It is unclear when the other children will be released.
Mr Akanji said the church did not pay any ransoms because it is opposed to paying criminals, but he added the church was unable to stop the children's families from taking any actions they deem fit to secure their release.
A spokesman for the Nigerian Police, Mohammed Jalige, said security forces and civilian defence forces were on a routine rescue patrol on July 12th around the forests near the village of Tsohon Gaya when they found three exhausted kidnap victims roaming in the bush.
Two other students escaped on July 20th when they were ordered to fetch firewood from a nearby forest. Mr Jalige said they were undergoing medical examinations.
Gunmen have carried out a spate of mass abductions from schools in northern Nigeria this year, mainly seeking ransoms.
Separately, gunmen have seized a negotiator who had been sent to pay ransom money to secure the release of 136 students kidnapped two months ago, the school and parents said.
Abubakar Alhassan, director of the Islamic school, said the school and parents have been negotiating with the kidnappers who demanded 30 million naira (€62,000) to release the students from the school.
Mr Alhassan said the school had contributed to a ransom and some parents sold property to raise cash but they said the negotiator, a 60-year-old man from the community, was taken because kidnappers said the ransom he brought was short.
“We sold most of our properties and used our savings to see that our children are returned. Unfortunately after all the effort, they said that we did not bring the money as they required,” said Ibrahim Salihu, father of two of the children abducted by the school in Niger state.
“We are now left with nothing and our children are still held captive,” he said.
The police did not respond to a request for comment.
Kidnappings in Nigeria began with abductions by jihadist group Boko Haram and its offshoot Islamic State West Africa Province. Now criminal gangs have used the tactic.
Nigerian president Muhammadu Buhari, who won election on hopes that he would tackle Nigeria's security challenges, has not been able to do much in addressing the growing cases of mass abductions from schools. – AP, Reuters