ABUJA — Armed gangs kidnapped 163 Christian worshippers after storming two churches in Nigeria's northern Kaduna state on Sunday, a member of the clergy told AFP.

"The attackers came in numbers and blocked the entrance of the churches and forced the worshippers out into the bush," Reverend Joseph Hayab, head of the Christian Association of Nigeria for the country's north, said on Monday.

"The actual number they took was 172 but nine escaped, so 163 are with them," added Hayab, who lives in the city of Kaduna.

Gunmen raided the two churches during Sunday mass in Kurmin Wali village in the predominantly Christian Kajuru district.

It is the latest in a wave of kidnappings targeting both Christians and Muslims in Nigeria.

Gangs — known in Nigeria as "bandits" — frequently carry out mass kidnappings for ransom and loot villages in mainly the northern and central parts of the country.

Describing Sunday's attack, local police said gunmen armed with "sophisticated weapons" burst into the two churches in Kurmin Wali, a forest community in Afogo ward, at about 11:25 local time.

In November, more than 300 students and teachers were seized from a Catholic school. They were later released in two successive groups. It was among a spate of kidnappings that made international headlines.

Experts say corruption, poor intelligence sharing and underfunded local policing have hampered efforts to tackle the kidnappings and other problems.

Nigeria's defence minister resigned last month at the height of the kidnapping crisis, officially for health reasons, according to the president's office.

The US has recently become militarily involved in Nigeria, launching airstrikes on Christmas Day on two camps run by a militant group in north-western Nigeria.

Earlier this month, US President Donald Trump warned of more strikes if Christians continued to be killed in the West African nation.

There are more than 250 ethnic groups in Nigeria, which is roughly divided into a mainly Muslim north, a largely Christian south, with intermingling in the middle - and the government says people of all faiths have been victims of attacks.

A Nigerian foreign ministry spokesman responded to Trump's warning by saying that Nigeria would continue to engage constructively with partners such as the US.

''Nigeria remains committed to protecting all citizens, Christians and Muslims alike, without discrimination,'' Alkasim Abdulkadir said. — Agencies