A strong 7.3 earthquake shook an area in the Pacific Ocean off El Salvador early Monday, prompting a brief tsunami warning for the region that was later lifted, US officials said.

The epicenter of the tremor, which occurred at 0437 GMT, was located 111 kilometers (69 miles) south of the city Puerto El Triunfo in El Salvador, according to the US Geological Survey.

Following the quake the Pacific Tsunami Warning Center issued an alert, saying that the temblor, which took place at a depth of 54 kilometers (36 miles), had spawned a tsunami.

"Sea level readings confirm that a tsunami was generated," the center said, pointing out that the threat extended to all Central American nations and Mexico.

It warned that this tsunami may be "destructive along the coastlines of the region.

"Authorities in the region should take appropriate action in response to this possibility," the center said.

Shortly thereafter, the center said "the tsunami warning ... is now cancelled" for all of the affected area, Costa Rica, Nicaragua, El Salvador, Honduras, Guatemala, Panama and Mexico.

It was not immediately clear where the tidal wave had landed. No reports of casualties or damage were immediately available.

But in El Salvador, Civil Protection Service Director Jorge Melendez dismissed the tsunami threat.

"There is no tsunami alert," he told AFP in San Salvador. "The US Geological Survey has recorded a 7.4-point earthquake, but our observatory here recorded just a 5.7-point tremor."

According to Melendez, due to a significant distance from the epicenter, the earthquake was barely felt in El Salvador.

He said his agency did not issue an official tsunami alert, but said the people living along the coast should maintain "a certain level of vigilance."

The earthquake reading was based on the open-ended Moment Magnitude scale used by US seismologists, which measures the area of the fault that ruptured and the total energy released.

The initial USGS report put the strength of the quake at 7.4, but it was later revised to 7.3.

The quake was not the first reported in the region in the last 24 hours. Early Sunday, a 4.3 tremor was registered in the Pacific off the coast of Guatemala.

[Image via Agence France-Presse]