The grandson of 84-year-old former headmistress Louisa Denby last night remained in police custody after he was arrested on suspicion of her murder at the Shipley home they shared and the attempted murder of a nine-year-old boy.

Mrs Denby was found stabbed to death in an upstairs bedroom at the semi-detached home in Prospect Mount, Windhill.

Her 26-year-old grandson was arrested hours later, shortly after 4am yesterday, in Westfield Lane, Idle, Bradford.

He was also being questioned by detectives about the stabbing of the nine-year-old boy, named locally as Jason D’ Arcy, at the skate park in Windhill recreation ground, off Park Road, at about 4.40pm on Monday.

Detectives were quizzing him about a third incident which took place about ten minutes after the stabbing when a terrified eight-year-old girl was chased by a man through the garden of her home in Prospect Grove.

Detectives were yesterday examining a total of ten crime scenes connected to the investigation which is being carried out by the Homicide and Major Enquiry Team (HMET) at West Yorkshire Police.

Four other men, aged 29, 26, 24 and 18, have been arrested. Three remained in custody last night but the 24-year-old was released without charge.

But officers were yesterday at pains to reassure the public that they are not seeking anyone else in connection with the incidents.

Mrs Denby’s body was found in her home with numerous stab wounds at 11.59pm on Monday by police investigating the stabbing of Jason.

Yesterday, senior officers spoke at a press conference at Carnegie Skate Park, where their fast-moving investigations started on Monday afternoon.

They said there were no links between the victims and they were still trying to work out why the attacks had happened.

Detective Superintendent Lisa Griffin, who is leading the inquiry, said police were initially called to reports of a nine-year-old boy being stabbed at the skate park at Windhill Recreation Ground.

As she stood in front of the skate ramps, cordoned off with blue and white police tape fastened around trees, Det Supt Griffin said police had found a knife as part of their investigations and were still investigating at ten sites.

“Yesterday at 4.50pm, we had information that a nine-year-old-boy had been stabbed at the skate park here in Shipley,” she said.

Ten minutes later, a young child screamed as she was chased through her garden in nearby Prospect Grove.

Det Supt Griffin said: “We received information that an eight-year-old girl was playing in her garden when a male approached and tried to draw her attention and he chased her through the garden. She went into her home address, so nothing untoward happened.”

Inquiries into both incidents continued which led officers to discover Mrs Denby’s body.

Det Supt Griffin said: “It’s my belief at this time that the three incidents are linked and I base that assertion on the basis that the description of the suspects tallies with the incidents involving the children.”

The senior investigating officer said the force had been inundated with calls and thanked the community for its support.

“We’ve been appealing for information about the persons responsible and the public have been very good in responding to that. We’ve got lots of information that’s led to a number of arrests. We’ve got five people in custody at this time and the inquiries are still ongoing.

“Although we have made those arrests, we would still encourage the public to make any calls to us if they can possibly assist with further information.”

Jason had been playing with friends at the skate park near Carr Lane and was going to his home in Park Road for a drink when he was approached by a man.

“With no prior warning and for no reason known to us at this time, (he) was attacked with a knife,” Det Supt Griffin said.

Jason, a pupil at High Crags Primary School, Shipley, was undergoing surgery at Leeds General Infirmary yesterday. He suffered injuries to his arm and chest.

Three men, aged 18, 24 and 29, were arrested late on Monday evening in relation to the attack on the boy.

At 4.10am yesterday, a member of the public reported seeing a person matching the description of the suspect police were hunting in Westfield Lane, Idle.

A short time later, another 26-year-old man was arrested.

Chief Superintendent Angela Williams, the divisional commander for Airedale and North Bradford, told yesterday’s press conference: “The three incidents which took place here yesterday are very, very unusual. I know the community has been a little shook by it, as is expected.

“But we are not looking for anyone else. We have five men in custody, and currently have about ten scenes where there are extra officers outside premises or the skate park behind me with blue and white tape.

“That to anybody living here, I believe, would be quite worrying.

“But we need to be really clear here, we’re not seeking anybody else.”

Det Supt Griffin added: “I want to reassure people that incidents like this are extremely rare. Police will be carrying out extra patrols in the area in the coming days.”