Twenty-four female students who were kidnapped from their boarding school last week in the country's northwest have been released, the presidency announced on Tuesday.

"President Bola Tinubu has welcomed the release today of the 24 schoolgirls abducted by terrorists in Maga," Kebbi State, on November 17, said a statement from Bayo Onanuga, special adviser to the Nigerian president.

Authorities had said a gang armed with "sophisticated weapons, shooting sporadically" attacked the school overnight, leaving a school official dead and a security guard injured.

The assailants had kidnapped 25 girls, but one was able to escape soon after, authorities said.

'Copycat kidnappings'

While applauding security agents, Tinubu has requested they "make more efforts to rescue the remaining students still being held captive", Tuesday's statement said.

The Kebbi attack triggered other "copycat kidnappings" over the past week, it added.

More than 300 children have since been abducted from a Catholic school in Nigeria's central-western Niger state, while 38 worshippers were seized from a church in the east of the country.