Scientists say it was a small earthquake that shook houses in Chester and surrounding towns.

The U.S. Geological Survey says it recorded a 2.0 magnitude earthquake early Tuesday morning three miles northwest of the center of Chester.

Many people in the area called 911 to report that their houses were shaking. The state police dispatched troopers, but they weren't able to find any reason for the shaking.

Earthquakes are unusual in Connecticut.