Updated

Security firm G4S has deployed a specialist riot squad to a prison the English city of Birmingham after disturbances by inmates spread to four wings of the facility.

G4S is a private company which runs the prison.

The disturbance began at about 9 a.m. GMT (0400 a.m. EST) Friday.

The unrest comes at a time that Britain's prisons are under intense pressure. Members of the Prison Officers Association say violence and inmate suicides are rising.

Some 200 prisoners rioted last month at Bedford Prison in southern England and guards also staged a walkout before courts ordered them to return to work. The prison officers union says "the service is in meltdown," with poor morale making it hard to retain staff.