At least seven men have raped a 39-year-old Swiss woman camping with her husband in an Indian forest, police say, the latest victim of sexual violence against women in the country.

The Swiss woman and her husband were touring the impoverished Madhya Pradesh state by bicycle and were camping overnight in the forest when at least seven men attacked the couple on Friday night, sexually assaulting the woman and robbing the pair.

"[The attackers] tied up the man and raped the woman in his presence." - Local police official SM Afzal



The attackers "tied up the man and raped the woman in his presence", local police official SM Afzal said, adding that they stole 10,000 rupees ($185) and a mobile phone from the woman.

The couple were on their way to the tourist destination of Agra, home to the iconic Taj Mahal monument, in northern India when they stopped to camp for the night near a village.

"The victims, who belong to Switzerland, put up a tent to stay overnight," when the attack occurred, Afzal said.

Indian media reports said the men were wielding sticks when they attacked the couple.

After the attack, the victim was admitted to hospital in Gwalior city, local police official MS Dhodee said. She was conscious on Saturday and speaking to authorities. No other details of her condition were known.

Suspects arrested

Dhodee said that police were still investigating the case but added that a "rape case has been registered against seven unidentified people".

Local police superintendent CS Solanki said police were questioning 13 men in connection with the attack.

"We are deeply shocked by this tragic incident suffered by a Swiss citizen and her partner in India," the Swiss foreign ministry in Bern said in a statement.

The ministry said its diplomats in India were in contact with local authorities and that it hoped the attackers would be "swiftly identified and would appear before a court to answer for their actions".

The attack on Friday night comes three months after a 23-year-old physiotherapy student was gang-raped and beaten in a moving bus and thrown bleeding on to the street in a case that sparked outrage in the country.

She died later in hospital in Singapore.

After the student was raped and beaten in Delhi last December, millions of Indians took to the streets demanding the death penalty for her attackers and official action to reduce the number of assaults on women.

Four men and a juvenile are on trial for that attack. A sixth defendant, who police say was the ringleader, was found dead in his cell on Monday.

One woman is raped every 20 minutes in India, according to the National Crime Records Bureau.

But police estimate only four out of 10 rapes are reported, largely due to victims' fear of being shamed by their families and communities.