A former army sergeant who survived a devastating IRA bomb blast has stabbed his two children to death before killing himself in a countryside bridleway.
The bodies of Michael, 51, Ben, seven, and Freya Pedersen, six, were found next to a Saab 900SE convertible car in the tiny lane at Newton Stacey, near Andover, Hampshire, at 6.15pm yesterday.
Mr Pedersen was a former army sergeant in the Household Cavalry unit that was hit by an IRA nail bomb in Hyde Park in 1982. Four soldiers and seven horses were killed in the explosion.
The children's maternal grandfather, William Clifford, 67, from Buckinghamshire, said outside his daughter Erica's home in Ashford, Middlesex: "We are obviously devastated and what we would ask is that you respect our privacy in this matter.
"It is extremely distressing and that is all I want to say."
Det Sup Tony Harris, of Hampshire police, said that the "tragic" incident happened while Mr Pedersen was on an arranged visit with the two children from his estranged wife.
Mr Pedersen, of Chertsey, Surrey, had taken the children to visit his father in Andover but failed to return the two youngsters to their mother by the pre-arranged time of 5pm.
The bodies were found lying behind the car at 6.15pm by a walker.
Mr Harris said police were tracing the family of Mr Pedersen, who had two other children from a previous relationship, when his estranged wife raised the alarm at 7pm.
He said he believed the deaths happened sometime that afternoon and he was not looking for anyone else as part of the inquiry.
Mr Harris said: "A Home Office pathologist visited the scene and at this time it appears the children suffered fatal stab wounds and Mr Pedersen took his own life shortly afterwards."
He added: "They were visiting relatives in Andover, which is nearby.
"It was the father of Mr Pedersen, the grandfather of the children."
Describing the incident, he added: "Any scene you go to with children involved is distressing for the officers, we have given them support and they continue to receive support.
"It is very tragic, it's a dreadful loss of life, one of the most tragic cases I have had to deal with."
He added: "It's very isolated and there was a person walking yesterday who notified us to the presence of the vehicle but I do not anticipate anyone else would have seen anything."
The children's mother was informed by a family liaison officer and was being provided with support, he said.
The 1982 bomb attack hit as Mr Pedersen's unit was taking part in a changing of the guard ceremony.
Four soldiers and seven horses were killed in the explosion, which left Pedersen's horse Sefton seriously injured.
Despite 34 separate wounds that required eight hours of surgery, the animal survived and became famous for battling against the odds.
Sefton became a symbol of the struggle against the IRA and won the Horse of the Year, a prize Sgt Pedersen picked up on its behalf.
A Surrey Police spokesman said that the case was being referred to the Independent Police Complaints Commission.
He said: "Surrey Police can confirm we have had previous contact with the Pedersen family.
"Following the sad events of Sunday, September 30, the force will be referring this contact to the Independent Police Complaints Commission for review."