Canadian police probe sixth gas pipeline bombing

* Explosion caused leak, no injuries

* Blast near site of Wednesday bombing

* Search for saboteur continues

By Allan Dowd

VANCOUVER, British Columbia, July 4 (Reuters) - An explosion damaged a natural gas pipeline in northeast British Columbia on Saturday, the sixth attack on an energy facility in that area of the Canadian province in recent months.

The explosion about 8 km south of the community of Dawson Creek, British Columbia, caused a leak but no injuries and was heard by crews repairing wellhead equipment damaged in a bombing on Wednesday, police said.

"The elements of this incident thus far, are consistent with the previous blast sites and the RCMP considers this latest bombing linked to the others," the Royal Canadian Mounted Police said in a statement.

Pipeline owner EnCana Corp (ECA.TO) said 12-inch (30-cm) diameter line carried "sour" gas that contains hydrogen sulphide and can be deadly if breathed, but none had been detected by monitoring equipment and there was no threat to the public.

The incident caused pressure in the line to drop, which activated emergency valves that immediately shut down the pipeline and stopped the leak, the company said.

The bombings that began in early October have all targeted EnCana natural gas facilities near the communities of Dawson Creek and Tomslake, British Columbia. None of the attacks have caused injuries but have produced small gas leaks.

Investigators believe the saboteur is a resident of the area and that the incidents are linked to a letter sent to media before the first blast warning EnCana to stop drilling for natural gas in the area.

The letter also complained about the production of "crazy" gas, which officials have speculated may be a reference to sour gas production.

"This (latest explosion) does change the dynamics of the events in certain terms, the main being our heightened concern for public safety, given that this explosion went off in close proximity of working crews and within a couple of kilometers of a populated rural area," the police statement said.

Unlike with the earlier explosions, police were alerted to this blast almost immediately after it happened and were able to reach the scene quickly, which investigators said may aid their search for clues.

Police had complained they believed some residents knew information about who might be responsible for the attacks but were unwilling to cooperate with investigators.

"We are greatly encouraged by the quick response from the public in this latest incident with the receipt of an unsolicited report," police said.