The body of a woman has been found in a house in Blyth.
Officers were led to the address in Holywell after an earlier car crash in Shiremoor.
A woman has been taken to the Royal Victoria Infirmary in Newcastle in a serious condition.
Both scenes are currently being examined by police.
– Dianne Winship, Northumberland Area Command Temporary Chief Superintendent
We are at the earliest stages of an investigation into today's events.
We are not in a position to release any further information at this time.
Local residents can be reassured that we will have extra officers in the area not only as part of the investigation but also to address any concerns people may have."