BANGKOK -- Two British tourists were found brutally murdered on the tourist-attractive island Koh Tao of Thailand on Monday morning.

Police and local villagers have been hunting for attackers by checking all boats leaving the island.

Police sources said the bodies were found stripped on Sai Ree Beach on the Surat Thani island popular for its full-moon parties and scuba diving.

Police described the two as British nationals, a 23-year-old woman and a 24-year-old man, according to the report of Bangkok Post.

Police suspect that the woman, whose skirt was hiked up to her waist and T-shirt pulled up, was raped.

Four meters away from her, the male victim was found naked on his back with a wound caused by a blunt blow to the back of his head.

A pair of shorts, a T-shirt and a denim skirt were found nearby.

About 50 meters from the victims, police found a blood-covered hoe, suspected to be the murder weapon, Thai media reported.

Local media also reported that the duo had probably been slain between 4 a.m. and 5 a.m. local time.

Residents told police there had been a beach party for about 50 people, mostly foreigners, on Sunday night that went into the early morning.

Police said they had no immediate suspects and were checking closed circuit TV cameras at nearby restaurants, hotels and shops in search of the attackers.

Investigators were also looking for witnesses who might know if the pair attended the beach party.

The double-murder has sent shockwaves through the island.

The chief of Surat Thani office of the Tourism Authority of Thailand said the murder could seriously affect Thai tourism, he urged police to speed up search for the killers.