Nigeria's government is making no meaningful effort to rescue more than 250 children abducted from a Catholic boarding school in the central state of Niger last Friday, the main Catholic cleric in the region has told the BBC.

But Bishop Bulus Dauwa Yohanna's accusation was disputed by the state's police chief, who accused the school of failing to co-operate with its search and rescue operations.

It is unclear who abducted the children from St Mary's school in Papiri village, but criminal gangs have been involved in kidnappings for ransom across Nigeria.

US President Donald Trump has threatened to intervene militarily in Nigeria if the government fails to stop the killing of Christians.

Nigeria is the most-populous state in Africa, with a large Christian and Muslim population. Its government says that people of all faiths and no faith are victims of insecurity in the country.

Militant Islamist groups are also waging an insurgency in Nigeria, with the government confirming last week that a senior army general had been killed by jihadists in an ambush in north-eastern Borno state.

Bishop Yohanna, who leads the Catholic church in the region and is the chairman of the Niger chapter of the Christian Association of Nigeria (CAN), told the BBC that the only official action taken so far to rescue the students had been to compile their names.

He disputed allegations made by the governor of Niger state, Umar Bago, in local media that the church had defied an order to close its school after threats of attacks. We did not receive any order at any point, the bishop said.

Niger state police chief Adamu Abdullahi Elleman told the BBC that enough officers had been deployed to Papiri, but the BBC did not see any when it visited the place—except for three at the school. He stressed that a search operation for the children was continuing and that the school was yet to report to his command.

The abduction at the school was the third to hit Nigeria in a week. Last Monday, more than 20 schoolgirls who are Muslim were kidnapped from a boarding school in Kebbi state. A church was also attacked further south in Kwara state, resulting in two deaths and dozens of abductions.

President Bola Tinubu cancelled a trip to the G20 summit to manage the crisis, assuring that he would not relent until every Nigerian is safe.