A group of 21 Nigerian Chibok girls brought home for Christmas after almost three years in captivity were prevented from celebrating at home with their families, several sources told AFP on Wednesday.

The 21 were among more than 200 mostly Christian schoolgirls released in October after being snatched by jihadist Boko Haram gunmen in April 2014 in a kidnapping that sent shockwaves across the world.

The group had been brought back to Chibok on Friday under heavy escort to spend Christmas at home but family and relatives said that instead they had been kept inside the house of a local parliamentarian for several days.

"What is the point of bringing them home if we as their parents can't see them?" said one of the fathers, who asked not to be identified.

A mother accused the government of "deliberately breaking our hearts in this festive period".

"We are a community and we take these girls as ours whether they are related to us or not," said local resident Ayuba Alamson.

A spokesman for the presidency Garba Shehu said in a statement late Tuesday that the officers in charge of protecting the girls had misinterpreted their instructions.

"There were some hitches arising from a lack of understanding of the objective of the trip on the part of some security operatives," he said, adding that instructions have "been given from headquarters for access by the parents to be eased".

Several dozen girls are still in captivity and those freed are watched over. Their capture had sparked a global Twitter campaign under the hashtag #BringBackOurGirls.