TOKYO (AFP) - A poetry-writing suspected killer was being hunted by Japanese police on Tuesday after the bodies of five people were found in a tiny mountain village.

The five victims represent a third of the population of the hamlet in western Yamaguchi prefecture, where police on Sunday night found three corpses after two houses were burned to the ground.

Investigators on Monday discovered the bodies of two more people.

Autopsies showed that all the five people died instantly after they were battered with a blunt instrument in the head. The police suspect the two homes were torched immediately after the three were killed, Kyodo News agency reported on Tuesday.

All five victims were in their 70s or 80s.

At the gutted home of Mr Makoto Sadamori, 71, and his wife Kiyoko, 72, two bodies were found and believed to be the couple, Kyodo quoted the police as saying.

The second home that was burnt down belonged to Ms Miyako Yamamoto, 79. A body was found there. Ms Yamamoto and the chief suspect were immediate neighbours.

On Monday, the police also found the bodies of Satoko Kawamura, 72, and Fumito Ishimura, 80 at their respective homes, Kyodo reported.

The chief suspect is a 63-year-old villager at whose home police found a "haiku" poem stuck to the window.

The haiku is a form of traditional Japanese poem, with a three-line verse of 17 syllables in a five-seven-five arrangement. It customarily evokes natural phenomena, frequently as a metaphor for human emotions.

The haiku reads: "Setting on fire - smoke gives delight - to a country fellow".

The man, whose name has not been made public, has a reputation in the village as a trouble-maker, reports said.