A policeman has died in the past hour after being stabbed in the chest during a anti-terrorist raid in Manchester.
Another officer also suffered serious chest injuries and a total of five officers were hurt.
Three men were arrested during the raid by immigration officials seeking to detain a man under counter-terrorism legislation.
The five injured officers were two detective constables, one detective inspector, one uniformed sergeant and one uniformed police constable, says a spokeswoman for Greater Manchester Police.
She was not able to confirm which officers suffered serious injuries.
No immigration officials were thought to be injured.
The road where the incident took place has been cordoned off and the building where the operation was carried out had all its curtains drawn.
Three men of North African origin were arrested, the spokeswoman said. She also confirmed that although the operation was connected to London's Metropolitan Police, officers who carried out the raid were all from GreaterManchester Police and the Immigration Service.
PA