More than 300 earthquakes have erupted at Washington's Mount Rainier this week, the largest earthquake swarm at the volcano since 2009.

SEATTLE (AP) — Officials are tracking the largest swarm of earthquakes in more than 15 years on Washington’s Mount Rainier but say there is no indication that the cluster of quakes is cause for concern.

Mount Rainier was experiencing "the most significant seismic activity" at the volcano in more than 15 years as an "earthquake swarm" hit the site starting on Tuesday.