A siege is under way at a house where a police officer was shot and seriously injured as he tried to make an arrest.
Pc Lomas, a local community beat manager, joined the force in 2001
Officers were at an address on Hardman Avenue in Rawtenstall, Lancs, when Pc David Lomas, 34, was shot in the chest. His injuries are not life-threatening.
Police confirmed a shotgun was used and said armed officers were at the scene.
A half-mile cordon is in place around the house where a man is understood to have barricaded himself inside. Nearby homes were evacuated.
A shelter was set up for residents at nearby Balladen School.
Lancashire Police said that Pc Lomas, who is single, is a local community beat manager from Bury in Greater Manchester. He joined the force in August 2001.
He was in a comfortable condition at the Royal Preston Hospital.
Ch Supt Jerry Graham said: "Although he has relatively short service with Lancashire Police he is very highly regarded and very well respected by his fellow officers."
He said two officers had gone to the house on Monday on a "routine inquiry" and the violent response "could not have been anticipated".
"We are able to confirm that the weapon involved was a shotgun," he added.
Ch Supt Jerry Graham appealed to people who live within the cordoned off area not to try to get home but to wait elsewhere until the situation had been resolved.
Jan Berry, chairman of the Police Federation which represents rank-and-file officers, said: "This incident just demonstrates the kind of dangerous situations police officers are facing on our streets every day.
"Our thoughts are with the officer at this time.
"A proper investigation needs to be carried out as to the circumstances that surrounded this terrible event."