A murder investigation has been opened after police found the body of a young woman following the arrest of an armed robbery suspect.
West Yorkshire Police are also trying to track down a man and woman they believe "may have come to harm".
The 37-year-old man suspect was arrested after the force received reports of an armed robbery at an Asda in Dewsbury, at 9.21pm on Saturday.
He was arrested at the scene in possession of a knife, police said.
The suspect later informed officers about a woman who he believed to be dead inside a house on Norfolk Street in Batley.
The body of a woman in her 20s was discovered following a search of the property.
The armed robbery suspect was later arrested on suspicion of murder.
A police spokesperson said formal identification has not yet taken place.
Detective Chief Inspector Dan Bates, of the homicide and major enquiry team, said: "This is clearly a very serious incident, where a young woman has lost her life."
There is a heightened police presence in Dewsbury today as we work to establish the full circumstances surrounding this incident.
"Our immediate priority is to identify and locate the two people and establish whether or not they have come to any harm
"A murder investigation is also under way and we do not believe there is any wider risk to the public at this time.
"We recognise this inquiry will cause concern in the community; we are working closely with our colleagues in the local neighbourhood policing team, who have stepped up patrols in the town centre."