HANOI, Vietnam - A tour boat sank early Thursday in Vietnam's scenic Ha Long Bay, killing eleven foreign tourists and a Vietnamese guide, officials said.

Twenty-one foreign tourists were on the live-aboard boat when it went down about 5 a.m. near Titov island, said Vu Van Bot, a police investigator in Quang Ninh province. The total number of people on the boat was not immediately known.

Twelve bodies have been found, including those of tourists from the US, Australia and Britain. All of the bodies have been sent to Bai Chay Hospital for identification. The body of a Vietnamese tour guide was also recovered, said Ngo Van Hung, director of Ha Long Bay's management board.

Nine foreign tourists and six Vietnamese were rescued, and efforts were under way to find others who may still be missing.

Giang Quoc Hung, deputy director of the hospital, said three foreign tourists, including men from the US and France and a woman from Switzerland, were admitted to the hospital for treatment of minor injuries.

"They were in panic," Hung said "They were given first aid treatment and have already returned to their hotels."

Online newspaper Dan Tri quoted Do Thong, provincial vice governor, as saying the tourists on board were from 11 countries, including the US, Britain, France, Russia, Denmark and Sweden.

Bot said police were contacting local weather forecasters to determine whether the seas were rough at the time of the incident.

Ha Long Bay is a tourism hotspot in Vietnam, located about three hours east of the capital, Hanoi. Many visitors opt to stay overnight on boats with sleeping cabins to cruise the picturesque bay, which is dotted with limestone formations.