Traffic is backed up for blocks in downtown Seattle this afternoon.

Seattle police say traffic is backed up for blocks in downtown Seattle Wednesday afternoon because of an immigration protest and a Mariners game.

People protesting for immigration overhaul are holding a rally in the middle of the intersection at Second Avenue and Madison Street, causing a major traffic disturbance, police said.

In addition, a Mariners game scheduled for 7 p.m. has people pouring into the blocks surrounding Safeco Field.