Earlier, Police in Madhya Pradesh said on Sunday that they have detained 20 men after a Swiss woman on a cycling trip with her husband was gang-raped.
No arrests have been made so far, but police were questioning the men in connection with the rape on the woman on Friday night in Datia district of the state, said senior police officer DK Arya.
The couple told police that the woman had been raped by seven or eight men, but that it was dark and they could not be sure of the exact number, Arya said. They said the husband also was attacked by the men.
The woman, 39, was treated on Saturday at a hospital in the nearby city of Gwalior and was released later that day, police said.
As an initial step, police registered a rape case against seven men and are searching nearby villages for other suspects, Arya said.
The couple, who were on a three-month vacation in India, had had visited the temple town of Orchha and were planning to cycle to Agra to visit the Taj Mahal, nearly 210 kilometers (130 miles) away.
They set out from Orchha on Friday and pitched their tent in a forest near Jatia village when they were attacked by a group of men armed with wooden sticks, police said.
The men beat up the husband, tied him to a tree and then raped the woman, police said.
The Swiss ambassador in India, Linus von Castelmur, has spoken to the couple and has demanded a swift probe of the incident by Indian authorities.
Castelmur said he was "most distressed" by the incident and has assured the couple of the Swiss government's help and support.
"Their health and treatment is the priority of the moment," the Swiss Embassy said in a statement.
The embassy said it was in touch with local authorities in Madhya Pradesh and has urged a "swift investigation and for justice to be done."