NEW DELHI: An American woman was gang-raped in the northern Indian resort town of Manali, police said.

Three men in a truck picked up the 30-year-old woman as she was hitchhiking to her guest house after visiting a friend, police officer Sher Singh said.

The men drove to a secluded spot and raped her, he said. She went to police and they filed a rape case.

Authorities issued an alert for the three men and set up roadblocks to check any trucks leaving the town, he said. No arrests had been made as of Tuesday afternoon, Singh said.

The rape came after a Swiss tourist was gang-raped in March while on a cycling trip through rural India. Six men were arrested in that attack.

The same month, a British woman traveling elsewhere in northern India jumped from a third-floor window fearing a sexual attack after the hotel’s owner tried to force his way into her room.

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

In response, the government passed a law increasing prison terms for rape and providing for the death penalty in cases of rape that result in death or leave the victim in a coma.

It also made voyeurism, stalking, acid attacks and the trafficking of women punishable under criminal law.