Mexico City: A powerful 7.3-magnitude earthquake struck off the southern Pacific coast of Mexico on Friday, near the country's border with Guatemala, sending tremors across parts of southern Mexico, Guatemala and El Salvador.

According to the US Geological Survey (USGS), the earthquake's epicentre was located about 48 kilometres southwest of Aquiles Serdán, off the coast of the southern state of Chiapas, at a depth of 15 kilometres.

The main quake was preceded by a smaller tremor with an epicentre further out in the Pacific Ocean.

The earthquake was widely felt, including in Mexico City, hundreds of kilometres from the epicentre, as well as in neighbouring El Salvador.

Authorities in Mexico and neighbouring countries said there were no immediate reports of major damage or casualties. Officials were assessing the impact while emergency response agencies continued to monitor the situation.