An elephant in northern Thailand went berserk Wednesday, killing his "mahout" keeper before running off into the jungle with three terrified Chinese tourists still on his back, police said.

"The mahout who was killed was Karen and he was not familiar with the elephant. They (the tourists) are safe now," Colonel Thawatchai Thepboon, police commander of Mae Wang district in Chiang Mai province, told AFP.

The Karen are an ethnic minority widespread in northern Thailand.  

Police said the incident took place at 9.30am (0230 GMT) as a Chinese family of three -- a father, mother and a young child -- took a ride on the back of a male elephant.

Rides are a popular and lucrative tourist activity but many animal rights groups say it is cruel and stressful for the pachyderms.

The elephant had not taken easily to his new keeper and turned on him suddenly, goring him to death, Channel 3 reported.

The channel broadcast footage of the three frightened tourists being led back to camp still on the elephant's back once it had been calmed down by other mahouts and their rides.

Thailand's roughly 4,000 domesticated elephants outnumber an estimated 2,500 remaining in the wild.

Domestic elephants in Thailand -- where the pachyderm is a national symbol -- have been used en masse in the tourist trade since they found themselves unemployed in 1989 when logging was banned.

Accidents are not unheard of. In June an elephant killed a Thai man and injured another as they were eating dinner at a beachside restaurant. The pair had been talking to the animal's mahout when it suddenly flipped.

Rights groups have documented the more unscrupulous mahouts using controversial techniques to crush the animal's spirit or severely overworking their rides to make more money.

"Elephants work every day, of every month, basically 365 days per year," Edwin Wiek, a campaigner from Wildlife Friends of Thailand told AFP.

"If you had to do the same, you would get stressed. It is the same for elephants. At some point they become crazy and we can't control them."

The accident comes as Thailand's tourism industry reels from last week's bombing of a religious shrine in Bangkok, an attack that killed 20 people, mostly ethnic Chinese devotees from across Asia.