A MASKED maniac exposed himself to two boys after producing a kitchen knife from his pocket.

Now police are appealing to the public for information into the terrifying ordeal in Astley Park, Chorley.

Police revealed that four youths -- two of them female -- were playing in woods in the park when the man, wearing a 'Scream' mask and grey cloak, approached.

The two girls screamed and panicked and began to run away shouting for help while the boys remained on a swing.

Police said the man then produced a brown handled kitchen knife from his pocket and began waving it around before placing it back in his pocket.

He then undid his cloak and indecently exposed himself to the two boys before buttoning up his cloak and lifting his mask to reveal his face.

The boys ran away but were chased by the man who then made off after spotting a member of the public.

The offender is described as 6ft-6ft 2ins tall, aged 40, with short brown hair. He was said to have a slim to medium, muscular build. He had blue eyes and a goaty beard.

Police are urging anyone with information about the incident -- at around 2.15pm on Friday, August 11 -- to come forward under their Crimestoppers Appeal.

Calls will be treated in the strictest confidence and there could be a reward.

Anyone who can help should ring 0800 555 111.