A persistent molester is being hunted by police.

He was on a 104 bus on Wednesday, July 20 at around 4pm travelling between Barking Road, East Ham and Plashet Road, when he targeted his 17-year-old victim.

She boarded the bus in Green Street, Upton Park and took a seat at the back. The bus began to empty with passengers when the man next to her began to stroke her knee.

Feeling uncomfortable, she moved to a different seat only to be followed by the pervert who started stroking her back.

She again moved seats, this time sitting next to a woman.

Again he followed her and standing next to her he started touching her knee.

It was then her fellow passenger stepped in, marching him off the bus at Amity Road, Stratford.

But he followed them and only walked away when they shouted at him.

The man is described as black, aged between 20 and 22, 5ft 4ins, wearing a light blue football shirt and shorts and carrying a JD sports bag.

Anyone with any information is urged to call Det Con Jose-Paulo Qureshi at Newham police on (020) 7275 5711, or to remain anonymous call Crimestoppers on 0800 555 111.