Three prison officers have been attacked by Hashem Abedi, the brother of the Manchester Arena bomber, a source has told the BBC.

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 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, adding police were investigating.

As of 16:00 BST on Saturday, one female officer treated in hospital had been discharged.

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

“It’s a difficult day at the prison when colleagues are seriously hurt. You can’t help asking yourself why you do this job when something like this happens,” they added.

Abedi is the brother of Salman Abedi who carried out the Manchester Arena bombing which killed 22 people in 2017.

After Hashem Abedi, 28, was named by the Prison Officers’ Association as being involved in the attack, a government source confirmed to the BBC he was the prisoner involved.

Abedi was found guilty of 22 counts of murder, attempted murder and conspiracy to cause an explosion likely to endanger life in 2020 following the Manchester Arena attack.

In 2022, Abedi, along with two others, was found guilty of a previous “vicious attack” on two prison officers.

Saturday’s attack took place in a separation centre used to hold the country’s most dangerous and influential extremist prisoners. The centre holds less than 10 inmates. Abedi has been a long-term resident.

Following the incident, the chair of the Prison Officers’ Association, Mark Fairhurst, said the freedoms given to prisoners in these centres should be reviewed.

“I am of the opinion that allowing access to cooking facilities and items that can threaten the lives of staff should be removed immediately,” Mr Fairhurst said.

“These prisoners need only receive their basic entitlements and we should concentrate on control and containment instead of attempting to appease them. Things have to change.”

A Durham Constabulary spokesman has confirmed an investigation is under way following a “serious assault” at HMP Frankland.

The spokesman also said that two victims remain in hospital with “serious injuries”.

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.”

Additional reporting by Cachella Smith