Iceland declared a state of emergency, and officials are evacuating thousands of residents over concerns of volcanic activity.

The Icelandic Meteorological Office has recorded thousands of earthquakes in the country’s southwest region over the past several days. Police began warning residents of the coastal town of Grindavík to evacuate Friday, fearing a magma tunnel forming underneath the ground, according to CNN.

“Seismicity along the magma intrusion continues, although the size and intensity of the activity is decreasing. Since midnight today, 13 November, around 900 earthquakes have been detected. The seismic activity is concentrated on the region of the intrusion, between Sundhnúkur and Grindavík at a depth of about 2–5 km,” the Icelandic Meteorological Office posted in an update Monday morning.