Drivers are being asked to avoid North Main Street in Branford on Sunday.
Police said North Main Street is closed to all traffic between Cherry Hill Road and Cedar Street. The road is expected to be closed for the next several hours.
An NBC Connecticut crew at the scene saw at least one car involved in a crash still at the scene.
Anyone driving in the area is asked to use Main Street as a detour.
It is unknown if there are any injuries. No additional information was immediately available.