Manhunt sparked after elderly couple are threatened at knife point in Southsea on Christmas Day

The worrying attack took place at 8pm as the victims '“ who are in their 80s '“ were in St Vincent Road, Southsea.

The man approached the pair of pensioners and threatened them with a knife before being '˜scared off' by a passing motorist, police said.

The couple were not injured. However, detectives have launched a manhunt to find the knifeman.

He is white, aged in his 40s or 50s and around 5ft 6ins and was wearing a black jacket, black woolly hat and black trousers.

Detective Inspector Abigail Leeson, said: '˜I would like to speak to anyone who has any information about this incident, particularly the occupants of the vehicle which drove by at the time of the incident.  '˜The vehicle they were in is described as a medium-size black car.  If this was you, please call us as soon as possible as you may have vital information.'

Anyone with any information should contact Hampshire Constabulary on 101 quoting 44180477570.