A Japanese woman has accused an Indian tourist guide of drugging and then raping her in the historic city of Jaipur, police said, the latest in a series of sex attacks on foreigners in the country.

The 20-year-old told police the guide offered to show her around Jaipur on his motorbike on Sunday before assaulting her in an isolated part of the city in the evening.

"The accused offered to drop her at the hotel in the evening but took her to a desolate area... and allegedly raped her," Dharam Chand Jain, police inspector general for Jaipur district, told AFP.

The man fled the scene after the woman's screams were overheard by villagers who rushed to help, according to local media reports.

The woman said she was given food laced with drugs before being attacked by the man thought to be aged about 25, inspector general Jain said, adding that blood tests had been conducted on the woman to determine the type of drugs used.

The case is the latest in a string of high-profile sex attacks that have highlighted high levels of violence against women in the world's second-most-populous country.

Six men from the eastern city of Kolkata were charged last month with kidnapping and gang-raping a 22-year-old Japanese tourist.

The woman was allegedly held hostage for a month after travelling to the Buddhist shrine of Bodh Gaya in neighbouring Bihar state.

India has faced intense scrutiny over its efforts to curb violence against women following the fatal gang rape of a medical student in New Delhi in December 2012, which sparked a global outcry.

The Japanese embassy said it was gathering information about the attack and could offer no further comment.

Sexual violence hurts tourism

The attack risks handing another blow to the country's tourism industry. Britain and France revised their travel advisories for India last January, warning visitors about the risk of sexual attacks, after two cases of foreigners being raped.

"After such incidents tourism is the first casualty," Gour Kanjilal, executive director of the Indian Association of Tour Operators, told AFP.

"We have been issuing instructions to tourists not to accept help or food from strangers," he said.

Jaipur and the rest of Rajasthan state draws thousands of tourists every year to its palaces and forts built by the former Maharaja rulers, some in dusty-pink sandstone.

Sex attacks against women from Western countries have received major media coverage in India while similar attacks on local women have drawn only a fraction of the attention.

Last January, a 51-year-old Danish tourist was robbed and gang-raped at knifepoint in Delhi in a case that also grabbed national and international headlines.

In 2013 a Swiss cyclist holidaying in the central state of Madhya Pradesh was robbed and raped by five men, all of whom were later jailed for life.

AFP