Jul. 2, 2009 (United Press International) -- A Canadian natural gas pipeline in northern British Columbia has been damaged by an explosion for the fifth time since October, officials said Thursday.

The Royal Canadian Mounted Police anti-terrorism unit was sent to the isolated area near Pouce Coupe in the northeastern part of the province after an EnCana (NYSE:ECA) employee discovered the damaged wellhead, the Vancouver Sun reported.

Company spokesman Alan Boras told the newspaper the blast apparently happened overnight Tuesday.

"This appears to have some similarities to the previous incidents, that's why the RCMP have been called in," he said.

Boras said there had been no communication from anyone claiming responsibility for the attacks since the first blast last October. Just before the first explosion, a local newspaper received an anonymous letter calling for EnCana to stop flowing natural gas containing deadly hydrogen sulphide through the area.

The most recent pipeline attack was Jan. 4, the Sun said.