The RCMP say despite collecting 1,400 exhibits and interviewing more than 450 people, they still haven't solved the bombings of natural gas lines in northern B.C.

They say a June 11 explosion in a garbage can near Pouce Coupe appears to be unrelated to four earlier bombings that targeted EnCana (TSX:ECA) facilities.

Those blasts occurred between last October and January, but no one was hurt and most of the damage was minimal.

RCMP spokesman Sgt. Tim Shields says 250 investigators have been on the case, spanning B.C., Alberta, central and eastern Canada and the U.S., but no charges have been laid.

He says investigators have also been unable to determine if 85 sticks of an explosive and 24 blasting caps stolen from a drilling site near Chetwynd last summer were used on the infrastructure explosions.

Shields says investigators are still seeking tips from the public and reminds people that EnCana is offering a $500,000 reward for information in the case.