Oil-coal train protesters block tracks at Burlington Northern Santa Fe yard in Everett

About a dozen demonstrators blocked railroad tracks Tuesday morning at a Burlington Northern Santa Fe yard to protest train shipments of oil and coal and proposed export terminals in the Northwest.

Protesters included one person suspended from a tripod over the tracks, according to organizers with the group Rising Tide Seattle. Others are locked to the legs of the tripod.

"People in the Pacific Northwest are forming a thin green line that will keep oil, coal and gas in the ground," spokeswoman Abby Brockway said in a statement. "Just one of these proposed terminals would process enough carbon to push us past the global warming tipping point — we won't let that happen."

The demonstration started about 6 a.m. and blocked freight trains at the yard near Interstate 5, said railroad spokesman Gus Melonas. The main line remained open.

Everett police were standing by and letting Burlington Northern Santa Fe police handle the situation because it's a trespassing issue, said Officer Aaron Snell.

Rising Tide Seattle says it's an all-volunteer collective dedicated to taking direct action to confront the causes of climate change.

Everett is about 30 miles north of Seattle.