US military engaged in heaviest fighting against Isis since fall of caliphate in Syria

American and British armed forces have in recent days engaged in the heaviest fighting against Isis since the fall of the terror group’s caliphate nearly three years ago.

The clashes began on Thursday when hundreds of Isis fighters attacked a prison in the northeastern Syrian city of Hassakeh in an attempt to free an estimated 3,000 of their fellow fighters, who have been detained there since the extremist group was defeated in its last stronghold in March 2019.

Also held at the prison are some 700 boys, most of whom were detained because their parents were members of Isis, and who have now been taken hostage by the group.

Special forces units from the US and UK subsequently joined the fight in support of the Syrian Democratic Forces (SDF), the US-backed and Kurdish-led group that controls the prison and surrounding territory, according to local reports.

The Rojava Information Centre, a monitoring group with sources on the ground, said those special forces had deployed snipers and were helping to coordinate air support by the US-led coalition to defeat Isis. Video from the outskirts of the prison showed what appeared to be Bushmaster armoured vehicles, which are used by British special forces in Syria, deployed to the fight.

The UK Ministry of Defence declined to confirm, or comment on, the deployment of British special forces “for reasons of operational security.”

On Monday evening, Pentagon press secretary John Kirby confirmed that US forces had been deployed to support the SDF in retaking the prison.

“We have helped provide real-time surveillance during the event. We have conducted a series of strikes through this days long operation to include the procession targeting of Isis fighters who were attacking the SDF from buildings in the area and we have provided limited ground support strategically positioned to assist security in the area,” he told reporters in a briefing.

Mr Kirby added that there had been “some limited ground support” such as the deployment of Bradley fighting vehicles across access points “to help block as obstacles.”

The large-scale and sophisticated attack by Isis fighters demonstrates that the group may have steadily rebuilt its strength in the time since it was defeated on the battlefield by the SDF, which was supported by a global coalition of countries led by the US.

Thousands of Isis fighters were detained when the group lost its last territory in 2019. At its peak, the group controlled large swathes of Syria and Iraq, including major cities and centres of industry.

The Guweiran prison in Hassakeh held around 3,000 of those fighters. When The Independent visited it in 2019, at least two British prisoners, one American and one German citizen — all suspected Isis members detained during the capture of Baghouz — were being held there.

The SDF said on Tuesday afternoon that some 550 Isis fighters had surrendered to its forces after days of heavy clashes. A spokesperson added that several buildings in the prison complex had been recaptured from Isis but that fighting was still ongoing, and that SDF fighters were conducting sweeps of the surrounding neighbourhoods for escaped prisoners.

It is unclear precisely how many fighters and prisoners have been killed in the clashes, but SDF officials told The Independent on Monday that at least 170 suspected Isis militants, 27 of its own fighters, and seven civilians had died so far.

By Tuesday, the SDF said it had liberated several buildings from Isis fighters but that an unknown number were holding out.

The fate of the estimated 700 boys being held hostage by Isis was also unclear. The youths have been detained by the SDF since the fall of Baghouz in 2019. On Monday, Save the Children said it had received reports that some had been killed in the fighting.

Sonia Khush, Save the Children’s Syria Response Director, said: “What we are hearing from Guweiran prison is deeply distressing. Reports that children have been killed or injured are tragic and outrageous.

“All those involved in the fighting at Guweiran prison have a responsibility to protect these children from harm, and we urge them to take all possible steps immediately to ensure that these children can leave in safety.”

Ms Khush added: “Responsibility for anything that happens to these children also lies at the door of foreign governments who have thought that they can simply abandon their child nationals in Syria. Risk of death or injury is directly linked to these governments’ refusal to take them home.”