Indian police have arrested three men for allegedly gang-raping an American woman in the northern resort town of Manali.

Three men offered the 30-year-old woman a lift in their truck as she was hitch-hiking to her guest house on Monday night, officers said.

Her complaint to police alleges they drove to a secluded spot and raped her.

Three men in their early 20s were arrested near Manali, which is near the northern end of the Kullu Valley in the state of Himachal Pradesh..

Concern about sexual assaults in India has heightened since the fatal gang rape of a woman on a bus in New Delhi in December sparked public protests demanding better protection for women.

In March, six men were arrested for the gang rape of a Swiss cyclist, and a British hotel guest jumped from a third-floor window fearing a sexual attack when the hotel owner tried to force his way into her room.

In response, the government has passed a law increasing prison terms for rape and making voyeurism, stalking, acid attacks and the trafficking of women punishable under criminal law.