The attack occurred at a high-security prison in northeastern England on Saturday. Abedi threw boiling oil and stabbed three prison guards with a homemade stabbing weapon.
One of the prison guards, a woman, was discharged from the hospital on Saturday, while two men were kept for treatment of serious burn and stab wounds.
According to the men's trade union, their condition is now stable.
Hashem Abedi was convicted of the terrorist attack at an Ariana Grande concert at Manchester Arena in 2017, when 22 people were killed. He carried out the attack together with his brother, suicide bomber Salman Abedi.
