NEW DELHI — Indian police said Thursday that they were closing in on six homeless men in the gang rape of a 51-year-old Danish tourist in New Delhi, a case that highlights the plague of sexual violence in the country and threatens to tarnish its tourism industry. Two other suspects were picked up Wednesday night and accused of taking part in Tuesday's attack, which lasted nearly three hours and happened near Connaught Place, a popular shopping area in the heart of New Delhi, police spokesman Rajan Bhagat said. “We have identified the culprits. All of them are vagabonds,” a police official said, according to the Press Trust of India news agency. The two arrested suspects appeared in a New Delhi court Thursday with their faces covered. They were ordered to be held in police custody for three days for further investigation. Violence against women in India has caused increasing alarm since the fatal gang rape of a 23-year-old Indian physiotherapy student in New Delhi in December 2012. Several foreign tourists also have been targeted in attacks that often get international attention, although Indian women are assaulted far more frequently. Tourism figures fell significantly in the three months following the 2012 gang rape, with visits by women dropping 35 percent, according to the Associated Chambers of Commerce and Industry of India. Although the industry appears to have bounced back, recent attacks on foreign women could have another chilling effect. Tourism accounted for 6.6 percent of India's GDP in 2012, the latest year for which figures are available. Two Danish travel agencies said Thursday that they had not seen a decline in bookings to India since this week's gang rape. Niels Amstrup, manager of the Jysk Rejsebureau travel agency in Aarhus, Denmark's second-largest city, said his company was monitoring the Danish Foreign Ministry's website for advisories on travel to India, but that so far none had been issued. Last week, an 18-year-old German charity worker said she was assaulted on a train in southern India by a fellow passenger. In March, a Swiss woman reported being gang-raped in central India as she and her husband camped out in a forest after bicycling from the temple town of Orchha. And in June, a 30-year-old American woman was gang-raped in the northern resort town of Manali as she was hitchhiking to her guest house after visiting a friend. Police said the Danish tourist was raped at knifepoint Tuesday after she approached a group of men for directions back to her hotel. Instead of helping her, the men lured her to a secluded spot and raped her repeatedly, according to police. One of the suspects in custody was found with the victim's glasses case and 1,000 rupees ($16) in cash, a police statement said. Last year, India's Tourism Ministry launched an “I Respect Women” campaign to reassure travelers. Some hotels also have introduced new programs focused on safety. Anasuya Basu, director of marketing at Le Meridien Hotel in New Delhi, said the hotel has designated rooms for single women and recommends that women only take hotel taxis. Public fury over the 2012 rape case has led to more stringent laws that doubled prison terms for rape to 20 years and criminalized voyeurism and stalking. But many women say daily indignities and abuse continue unabated and that the new laws have not made the streets any safer. Still, there has been a surge in the number of rapes being reported recently, suggesting women are emboldened to speak up. Between January and October last year, 1,330 rapes were reported in Delhi and its suburbs, compared with 706 for all of 2012, according to government figures. — AP