Counter-terrorism police are leading the investigation into an attack on three prison officers by Hashem Abedi, one of the men responsible for the Manchester Arena bombing.

The officers sustained life-threatening injuries on Saturday including burns, scalds and stab wounds in the attack at HMP Frankland in County Durham, the Prison Officers’ Association said.

Abedi, 28, who was jailed for life for helping his brother carry out the 2017 suicide bombing, threw hot cooking oil over the officers and used “home made weapons” to stab them, the organisation said.

The Prison Service confirmed three officers have been treated in hospital after an attack by a prisoner.

The female officer was discharged by 16:00 BST on Saturday. Her two male colleagues suffered “severe stab wounds” and remain in hospital where their conditions have “stabilised”, Mark Fairhurst, national chairman of the Prison Officers’ Association, said on Sunday.

Saturday’s attack took place in a separation centre at HMP Frankland where Abedi has been a long-term inmate.

That centre, which holds fewer than 10 inmates, is used to house prisoners regarded as the most dangerous and extremist.

Fairhurst said separation centres are “very well resourced – for obvious reasons” but “to allow that type of prisoner to access the kitchen and use utensils that can be used as weapons… [that policy] needs to be removed immediately”.

“We are demanding that with immediate effect they restrict and remove cooking facilities from separation centres,” he said.

“We are worried about the knock-on effects and copycat incidents.”

The separation model was introduced in 2017 with the aim of separating and controlling prisoners who present a risk that cannot be managed in a mainstream location, according to the Ministry of Justice.

Fairhurst told the BBC he was “appalled” that offenders in these locations were being “allowed the same privileges as normal location prisoners”.

“A separation centre is there for a reason,” he said. “All we need to do with those types of prisoners is give them their basic entitlements.

“Separation centres should be for control and containment because these people are not going to change their ideologies and they are intent on inflicting harm on everyone they come into contact with.”

A prison officer at HMP Frankland told BBC News “staff are shaken by what’s happened”.

“You can’t help asking yourself why you do this job when something like this happens.”

Abedi’s brother Salman Abedi carried out the Manchester Arena suicide bombing which killed 22 people.

Hashem Abedi was found guilty in 2020 of 22 counts of murder, attempted murder and conspiracy to cause an explosion likely to endanger life and sentenced to a minimum term of at least 55 years before he could be considered for parole.

The sentence was a record for a determinate prison term.

In 2022, Abedi, along with two others, was found guilty of a previous attack on two prison officers at Belmarsh Prison in south-east London.

A sentence of three years and 10 months for this attack was added to his previous minimum term.

Counter-terrorism policing (CTP)’s Cdr Dom Murphy said: “Given the nature of the incident [on Saturday], it has been agreed that CTP North East will lead the investigation, supported by Durham Constabulary.

“This is an ongoing investigation which is in its early stages, and we are working hard to establish the facts. Therefore, we are unable to comment further at this time.”

Following the incident, former prison governor John Podmore told the BBC this incident was a “catastrophic security failure” as he underlined this unit holds the “most violent and dangerous” offenders.

Justice Secretary Shabana Mahmood said: “I am appalled by the attack of three brave officers at HMP Frankland today. My thoughts are with them and their families.

“The police are now investigating. I will be pushing for the strongest possible punishment. Violence against our staff will never be tolerated.”

Shadow justice secretary Robert Jenrick called the attack “extremely concerning”.

“There are serious concerns about the prison leadership’s ability to contain the threat from Islamist extremist inmates,” he said.

“This deeply serious security failure must be a turning point,” he added as he referenced a previous social media post of his titled “Britain’s prisons are being overrun by Islamist gangs”.

A spokesperson for the Prison Service said violence in prisons “will not be tolerated”.

“We will always push for the strongest punishment for attacks on our hardworking staff,” they said.

A spokesperson for the Ministry of Justice said on Sunday their thoughts are with the two officers who remain in hospital.

“There will be a full review into how this attack was able to happen, alongside the separate police inquiry,” the spokesperson added.

“The Government will do whatever it takes to keep our hardworking staff safe.”