One of two police officers shot in western Pennsylvania while responding to a domestic incident has died, as authorities search for the suspected attacker.

The Washington County Coroner confirmed that one of the Canonsburg officers had died at a hospital in the city, but did not identify them pending the notification of relatives.

State police Trooper Melinda Bondarenka told reporters the incident began at 3:14am local time on Thursday in Canonsburg, 20 miles southwest of Pittsburgh,

Ms Bondarenka told reporters the officers were "ambushed upon their arrival" and immediately shot when they arrived at the scene, which 11 News reports was on Woodcrest Road.

Further police activity has been reported at West College Street, where a resident said they had heard two gunshots.

The surviving officer has been flown to a hospital in Pittsburgh. His condition remains unknown and his name has not been released.

Police and SWAT teams have been seen near at least two homes in the borough. It is not clear whether the suspect was in either of those homes.

Roads have been closed and residents have been told to stay inside their homes as the search for the suspected attacker continues.

Schools in the area will open two hours later than scheduled and some have been closed due to the heavy police presence.

No details have yet been released about what led to the shootings.