A magnitude 7.6 earthquake has struck this morning near Acapulco in Mexico.
The United States Geological Survey said the quake struck 52km northest of Ometepec and 183km east of Acapulco at a depth of 10km.
It was initially measured as magnitude 7.9, but was later downgraded to 7.6, and was followed by a strong aftershock.
No tsunami alert was issued by the Pacific Tsunami Warning Centre.
The first quake was strongly felt in Mexico City, with buildings swaying - sending frightened workers and residents into the streets.
"I have problems with pressure, I felt I was going to faint,'' said Rosa Maria Lopez Velazquez, 62, outside a mall in Mexico City.
A realtor in Acapulco, Pascal Clemens, told CNN the quake continued for almost two minutes.
There were no immediate reports of major damage or injuries from the quake, which was felt as far away as Guatemala and in some of the lower states in America.
President Felipe Calderon said there were no immediate reports of damage through his Twitter account.
The mayor of Mexico City Marcello Ebrard said on Twitter he was up in helicopter and had seen no signs of major damage.
He also said the water system and other "strategic services'' were not experiencing problems.
Acapulco is one of Mexico's biggest resort cities, 300kms southwest of the capital Mexico City.
A 6.2-magnitude earthquake struck the Papua region of Indonesia, but there was no tsunami warning or reports of damage.
The quake struck at 2:56 am local time at a depth of 66.9 kilometres, some 154 kilometres south southwest of Jayapura in Irian Jaya, the US Geological Survey said.
Indonesia sits on the Pacific "Ring of Fire'', where the meeting of continental plates causes high volcanic and seismic activity.
- Herald Online staff and agencies