Abbas is one of 54 teenagers Kurdish authorities are trying to de-radicalise at a reform center in the northern city of Dohuk for youths and women suspected of aiding Islamic State.

The idea is to prevent the hardline Sunni group from brainwashing a new generation of suicide bombers and fighters into threatening Iraq's stability again after an ongoing army offensive in their stronghold of Mosul ends.

"We encourage them to choose life, not death," said Zaki Saleh Moussa, head of the institution in the northern Iraqi city of Dohuk.

Reuters was given exclusive access to the facility and allowed to speak with Abbas, another 17-year-old boy and two adult women, all in the presence of interrogators.

All four prisoners denied that they wilfully supported the fighters, and said Islamic State had put pressure on them to cooperate. An interrogator said he was skeptical of those accounts and a court would determine the prisoners' fate.

"My uncle and cousin pressured me to join," said Abbas, sitting in a room with books on culture and art designed to open up new horizons for teenagers and women exposed to jihadist ideology.

"I had no choice. My family was in a feud with another one and they threatened to give those people my whereabouts and said 'we will let them kill you'," he said.

He spent 18 days at an Islamic State training center in Mosul for religious indoctrination. Abbas was given an assault rifle and assigned to a checkpoint where he was charged with catching anyone who broke the group's many rules.

"They told me to go sign up to be a suicide bomber and I said no. My sister and brothers are sick; I could not leave them. I quit after 15 days. They jailed me for three days and tortured me with a stick," said Abbas.

Many Mosul residents acknowledge having backed Islamic State when militants seized control of Iraq's main northern city in 2014. They initially regarded the Islamic State fighters, fellow Sunni Muslims, as protectors against the Shi'ite-dominated army.

Eventually Islamic State alienated Mosul with its beheadings and shootings of opponents and public whippings of people for enjoying simple pleasures like smoking or watching television.

Since October, the Iraqi army, federal police, special forces and Shi'ite militias have driven Islamic State out of the eastern half of Mosul and towns and villages around it, with air and ground support from a U.S.-led international coalition.

The western half of Mosul is the last major stronghold of Islamic State's self-proclaimed caliphate in Iraq. But once the city falls, Iraqi authorities fear the group will go underground and mount an insurgency. De-radicalisation programs are seen as a tool to reduce further security threats.

RELIGION OF PEACE

Bishra Abdullah, a 40-year-old woman also undergoing de-radicalisation at the Dohuk center, said Islamic State fighters had come to the family home, taken her 14-year-old daughter and married her off to a militant for two months.

"They brought her back and said, 'We don't need her,'" she said.

An interrogator said Abdullah was accused of sheltering jihadists. She denied it.

The teenagers at the Dohuk center are confined in groups of about 20 to a room with bunk beds and blankets. Above their beds are photographs of Kurdish leaders, people that Islamic State describes as infidels who deserve to die.

Social workers teach them that Islam is a religion of peace.

Ghaith Rajeb, a subdued 17-year-old who slurs his words, said he felt joining Islamic State was the only option as the militants jailed hundreds of people and forced others to pray and listen to fiery mosque sermons condemning non-Sunnis.

He too manned a checkpoint, where he was told to keep a close eye out for anyone who collaborated against Islamic State.

"No one could defy their orders," said Rajeb, whose cousin signed up with the militants and was never heard from again.

Rajeb is nostalgic for the days when he was studying to become a teacher and playing soccer with friends, another activity banned by Islamic State. But returning to Mosul depends on convincing the Kurdish authorities to release him.

"I would like to go back and study and see my family. But I don't know if there will be a court ruling," he said.

Moussa, the reform center director, was cautiously optimistic the re-education program would help prevent the youths and women from supporting Islamic State in the future.

"There are results. But more efforts are needed in this place because the number of people arriving here increases by the day," he said, as an interrogator looked on.