A SERIAL sex attacker is being hunted after a teenager was raped at knifepoint and another girl indecently assaulted.

Detectives today described the man, who wore a distinctive Hawaiian shirt during both incidents, as a danger to lone women.

And they have pledged to increase patrols in Blackburn in a bid to catch him before he strikes again.

Women have been urged to travel home from the town centre at night in taxis and not walk home alone.

The alert was sparked when a second woman told police she had also been attacked after reading details of the rape in yesterday's Evening Telegraph.

The 15-year-old rape victim was walking home from the town centre when noticed she was being followed along Byrom Street.

A man grabbed her from behind and forced her at knifepoint on to spare land near Sumner Street where she was raped.

Ninety minutes earlier, at 2.30am, a 19-year-old woman was followed by a man in Franklin Road, off Redlam, after she had left Heaven and Hell nightclub, Lords Square

He followed her along Redlam, into Spring Lane and then grabbed her from behind on Franklin Road.

She screamed as he indecently touched her, causing him to flee towards Redlam.

Both attacks took place on Sunday.

Det Insp Jim Elston said: "He presents a danger to lone females and, until such time as he is apprehended, we would urge all lone females to review their own security.

"They should not walk alone at night, stay in the company of family or friends, use taxis and stay within visible areas.

"Whilst he is at large, we will be targeting that area of Blackburn with an increase in patrols to reassure the residents and people visiting the area."

Concerned residents of Franklin Street, where one of the attacks occurred, said they were shocked.

One resident, who wished to remain anonymous, said: "I have two teenage daughters who normally walk home from their friends but now I shall make sure they have a lift whenever they go out.

"I used to think Blackburn was a safe town."

The attacker is described as white, in his late 20s to 40s, about 5ft 8in tall, slim and with long, brown hair. He was wearing glasses, a dark baseball cap, a bright orange or bright orange and red shirt and dark trousers.

Anyone with information can call police on 01254 51212 or confidentially on 0800 555 111.