BOSTON — Hundreds of climate change activists flooded Boston's Seaport District and forced police to close the Congress Street Bridge to traffic during rush hour Friday.

The protesters gathered for "Flood the Seaport" protest, which was organized by Extinction Rebellion. The event is meant to raise awareness about what organizers are calling a "climate crisis."

According to one report, sea levels in the Seaport District are projected to rise several feet over the next few decades.

Activists began to move onto the bridge at about 4:30 p.m. and built a temporary structure on it.

Two protesters then climbed about 40 feet up a structure on the bridge and placed a banner there that reads: "Tell the truth ... declare climate emergency."

According to John Atwater, of NewsCenter 5, police spoke sternly with the pair but did not arrest them.