Two dog walkers were subjected to indecent exposure by a man in separate incidents in Lings Wood in Northampton.
A police spokesman said the first incident took place on Friday at about 4.30pm.
“A 15-year-old boy was walking his dog through the park when he spotted a man hiding in the trees,” he said.
“Shortly afterwards he realised the man was walking behind him and stopped to let him pass, at which point the man turned around and indecently exposed himself to the boy.
“The boy loosened his dog’s lead, and the man ran off in the direction of St Peter’s School,” the spokesperson added.
The spokesman said the suspect was described as Asian, aged about 19-20 years old, about 5ft 7in, with a slim build and an unkempt beard. He was wearing a dark red hooded top and dark red tracksuit bottoms.
The second incident happened yesterday at about 3.45pm.
“A 42-year-old woman was walking her dogs in Lings Wood when she was approached by a man who asked for the time and a cigarette.
“He then pulled down his tracksuit bottoms and exposed himself. The woman walked away, and the offender walked off towards the car park,” the spokesperson added.
The man in this incident was described as Asian, in his 20s, 5ft 7in to 5ft 8in, with a slim to medium build. He had short, straight black hair and was wearing navy blue tracksuit bottoms and a khaki-coloured fleece.
Witnesses to either incident or anyone with any information, are asked call Northamptonshire Police on 101.
Alternatively, they can call the independent charity Crimestoppers anonymously on 0800 555 111 or use the anonymous online form at www.crimestoppers-uk.org.