A powerful 6.5 magnitude earthquake in the Pacific Ocean off the coast of El Salvador shook much of Central America from Nicaragua to Guatemala on Tuesday, sending residents in some cities streaming into the streets.

The US Geological Survey reported the epicentre was 43 kilometers south of Intipuca, El Salvador at a depth of 70 kilometers. That point is outside the Gulf of Fonseca where Honduras, El Salvador and Nicaragua all share coastline.

In El Salvador's capital, residents ran into the streets as the ground shook, but there were no immediate reports of damage or injuries. When a radio station open its phone lines to residents around the country, there was also no immediate report of victims.

In the country's Legislative Assembly, lawmakers fled their desks to get out of the building, before returning a short time later to resume the session.

The country's Environment Ministry advised that there was no threat of a tsunami.

In Nicaragua, the quake was felt strongly in the capital and all along the Pacific coast.

Nicaragua Vice President and first lady Rosario Murillo said there were no reported victims immediately in that country.