THREE people were slapped in the face by laughing thugs in a bizarre series of attacks in Burnley.

Police have launched an investigation after three separate assaults were reported to them in the space of less than half an hour on Sunday lunchtime.

Detectives are linking all three incidents, which they described as similiar "happy slapping".

However it is not known if the attackers were filming the slaps on mobile phones.

In the first incident a 52-year-old woman was walking her dog in Crown Point Road at about 12.45pm when she was approached by a man who hit her in the face.

She fell to the floor and the man ran off and climbed into a waiting blue car.

Five minutes later in Rossendale Avenue detectives said a 71-year-old retired man was walking along when a man in his early 20s ran up to him, slapped him in the face and started laughing.

He ran away and got into a blue car parked at the nearby Bull and Butcher pub.

At 1pm a 55-year-old man was walking in Moseley Road when he was approached by two men described as 17 to 18-years-old. He was slapped across the head and the attackers made off.

Insp Martin Selway, of Burnley Police, said: "These are being treated seriously as three unprovoked assaults on three people, one of whom quite elderly, minding their own business and out for weekend walks."

Police have arrested a 20-year-old man on suspicion of common assault. He is being questioned by detectives at Burnley Police Station.