Indian officials said an American tourist was gang -raped by a group of men in a hill resort in the northern part of the country, Reuters reported on Wednesday. The woman was picked up by three men in a truck on Monday night while hitchhiking back to her guest house in Manali, a town in Himachal Pradesh state, police said. She had been visiting friends, and reportedly was unable to find a taxi cab home.

While three men were briefly detained and then released in connection with the attack, Himachal Pradesh police chief B. Kamal Kumar told Reuters.

The woman told police the rapists took her to an isolated area, and assaulted her. She was taken to a local hospital for preliminary tests before being taken back to her guest house, said a local police inspector, who declined to be identified.

"We are in contact with authorities but due to issues of privacy we have no further comment," Peter Vrooman, spokesman for the U.S. embassy in New Delhi, said in an email.

A hospital test confirmed she was sexually assaulted.

This latest sexual assault follows a string of incidents, which has hit the country involving attacks on female tourists. In March, a Swiss tourist was gang-raped while on a camping trip in Madhya Pratesh.

 The National Crime Records Bureau says more than 24,200 rapes were reported across the country in 2011 -- about one every 20 minutes.

"Women should observe stringent security precautions, including avoiding use of public transport after dark without the company of known and trustworthy companions," a U.S. State Department travel advisory for India statement read.