Prime Minister David Cameron has reacted to this week's "truly shocking events" in Shipley, telling MPs at Commons question time: "We must make sure that justice is done."

"These were truly shocking events and reading about them this morning, particularly the young boy who staggered out of the park bleeding, having been stabbed, and the grandmother who was described as someone who was so much a community member that they were seen as everybody's grandmother, is truly disturbing."

He joined Shipley MP Philip Davies in praising the response of the police and local community.

A nine-year-old boy remains in hospital as detectives are investigating links between his stabbing, the murder of a retired teacher and an incident in which an eight-year-old girl was chased through a garden in West Yorkshire.

Jason D'Arcy was stabbed and left covered in blood in an apparently random attack in a skate park near his home in Shipley at 4.40pm on Sunday.

Ten minutes later, a young girl was chased through her garden in nearby Prospect Grove before taking refuge in her house. Detectives investigating the stabbing later found the body of 84-year-old Louisa Denby with multiple stab wounds at her home in Prospect Mount, shortly before midnight.

A 26-year-old man is being questioned on suspicion of murder and attempted murder, West Yorkshire Police said.