Britain and France have revised their travel advisories for India to warn visitors about the risk of sexual attacks following two rape cases involving German and Danish tourists in recent weeks.A 51-year-old Danish tourist was robbed and gang-raped at knife-point in Delhi on Tuesday after she lost the way back to her hotel and stopped to ask directions near Paharganj, an area popular with backpackers.Three men have been arrested and police are trying to locate another five suspects.On Monday, an 18-year-old German charity worker told police in Chennai that she had been raped on an overnight train by a passenger."Women travellers should exercise caution when travelling in India even if they are travelling in a group," the British advisory posted on the government website said.The French foreign office also advised its citizens to exercise "utmost caution" in an advisory updated on Thursday."Several recent incidents show that foreign women or expatriates can be the victims of such incidents in India," it said.

In December 2012, a 23-year-old student was fatally gang-raped on a moving bus in the capital in an attack that sent shock waves across the nation. Four men have been sentenced to death in that case.