Part of a four-lane freeway bridge over the Skagit River in Washington state, in the US, collapsed on Thursday (May 23), causing vehicles and people to career into the cold water below, authorities said.

The collapse on Interstate 5 occurred at about 7 p.m. local time (0200 GMT) in Mount Vernon, 55 miles (90 km) north of Seattle, a Washington State Patrol spokesman said.

The Seattle Times newspaper reported that three people were rescued from the water.

The cause of the collapse was not immediately known, but officials said it was not raining in the area and the state governor was due to give a news conference around 0600gmt.

The bridge was built in 1955, according to the website for the privately run National Bridge Inventory Database. The highway and bridge are the main corridor for car traffic between Seattle and Vancouver,Canada.

The Skagit County Sheriff's Office, in a statement on its Facebook page, asked people to avoid the area to make room for emergency responders.

The collapse comes nearly six years after another bridge fell in Minnesota and raised concerns about faulty infrastructure in the United States.

Presented by Adam Justice