A nun in Mozambique, who spent more than three weeks as a captive of jihadists, has raised the alarm about the growing numbers of children abducted by terrorists, many of whom are being forced to become child soldiers or brides.

Father Kriwiwi Fonseca, a priest ministering to families displaced by Islamist violence, told Catholic charity Aid to the Church in Need (ACN) about Sister Eliane da Costa’s ordeal – and relayed her stark warning that young people are being coerced by militant extremists.

Father Fonseca said: “Sister Eliane herself was held for 24 days by the terrorists, in the mountains, and she begged me, ‘Padre Fonseca, please don’t forget the people who have been abducted, above all the children and adolescents, who are being trained to become terrorists’.”

Father Fonseca went on to explain the motivations behind the abductions.

He said: “The terrorists use these children and forcibly train them to fight in their ranks, whereas the girls are raped and forced to become their ‘brides’.

“In some cases, when they have grown bored with them, these girls are simply thrown out.”

Sister Eliane da Costa, of the congregation of Saint Joseph of Chambéry, was kidnapped with Sister Ines Ramos last August when the northern town of Mocimboa de Praia fell into terrorist hands.

Father Fonseca added: “We can speak of hundreds, because if we include all the villages from where people have been abducted, we can undoubtedly state this much.”

The priest told the story of Mina, a woman whose children were abducted during terrorist attacks in Mucojo, Macomia district.

He said: “The terrorists found Mina at home with her husband, her brother and her four children.

“They told her, ‘We’re going to take these two boys.’ In the end, they took three boys, aged 14, 12 and just 10 years old…

“She was forced to watch as they cut the throats of her husband and her brother. Not only that, but her own little girl of two or three years old also witnessed the murders.

“The little girl is still in shock to this day and keeps insisting that they return to the town to see her father. She witnessed the entire scene.”

Father Fonseca said that the terrorists were hoping to increase their ranks.

He said: “I believe the object is radicalisation. We are talking of children and young people who were torn from their homes last year, or the year before…

“It’s a long time to be in contact with evil, and one ends up assimilating this evil. Interacting with them can end up converting them into the worst kind of terrorists…”

Mozambique has been dealing with an Islamist insurgency since October 2017, which, according to UN estimates, has displaced upwards of 700,000 and killed more than 2,600.

Father Fonseca said: “If they intensify this warfare and international allies, other governments and countries come to try and help Mozambique wipe out the terrorists, what will that mean? It means that many innocent children may also die…”

Last March, ACN agreed emergency aid of €160,000 (£136,500) to Mozambique, providing beans, flour, cooking oil and other foodstuffs for displaced people facing famine.