A serial rapist has been sentenced indeterminately after he was found guilty of a string of “vicious” attacks on young women.

Sunny Islam, 23, of Salisbury Avenue, Barking, was found guilty of seven counts of rape, one count of assault by penetration and one count of kidnapping at Woolwich Crown Court in August 2011.

Officers were first made aware of the assaults following the kidnap and rape of a 15-year-old girl in the Barking area in September 2010.

The teenager had been walking in the Docklands area with her friend when Islam grabbed her at knifepoint and drove her to a secluded road in Barking.

He threatened her before raping her in his Renault Clio.

Further investigations soon led to the other attacks.

The four female victims were aged between 15 and 30 years when the offences are said to have happened between May and September 2010.

Detective Chief Inspector John Sandlin, of the Homicide and Serious Crime Command, (HSCC) who investigated the offences, said: “These were a series of terrifying assaults carried out by a man who actively preyed on vulnerable women.

“I would like to express my thanks to all of the victims involved in this case. They came forward to give evidence, showing a huge amount of courage throughout this investigation, and we only hope that this result brings them some small comfort.”

He also encouraged other potential to come forward and speak to their local police station.

CPS London District Crown Prosecutor for Snaresbrook, Lionel Idan, added: “These were terrifying and frenzied sexual attacks on vulnerable victims and I would like to pay tribute to their courage in coming forward and testifying. Islam would patrol the streets looking for his victims and viciously attack them in the confines of a car.”

He was sentenced yesterday to 22 years in prison in relation to the rapes.

Islam was also sentenced to eight years imprisonment for the assault by penetration and an additional eight years for the offence of kidnap.

All of the terms are to run concurrently.

Islam will not be considered for parole until he has served 11 years.