Bangkok: Swarms of bees attacked a group of novice monks at a Buddhist temple in northern Thailand, causing 76 of them to be hospitalised, reports said Sunday.

Naren Chotirosnimitr, director of Maharaj Nakorn Chiang Mai Hospital, was quoted by the Bangkok Post as saying 19 of the 53 monks admitted to hospital were in serious condition.

He said six of the monks arrived at the hospital in a coma, with their blood pressure at a dangerously low level.

Naren said bee attacks can be fatal if patients sustain multiple stings and are allergic.

Sting victims typically experience nausea, difficulty in breathing and skin rash. In serious cases blood pressure drops sharply.

The monks were sweeping the grounds of the Chedi Luang Worwiharn temple in Chiang Mai province, 600 kilometres north of Bangkok, when the bees attacked.

Abbot Phra Ratcha Jetyajarn said he had no idea why the bees attacked.

He said the temple would continue to keep beehives on the grounds but will warn visitors to keep their distance.