(Photo: CGTN)

A shallow 6.6 magnitude earthquake struck off the coast of El Salvador on Thursday near San Salvador, according to the US Geological Survey (USGS).

The quake struck around 40 kilometers south of the capital at a depth of 65 kilometers, said the USGS. 

A tsunami warning was issued and classes in coastal areas were canceled.

The tremor was reportedly felt in several countries including Guatemala, Honduras and Nicaragua.

There have been no immediate reports of casualties.