Southern Mexico has been shaken by a 6.4 magnitude earthquake, causing power cuts and panic, but so far no reported injuries or damage.
The US Geological Survey said the quake's epicentre was about 110km (70 miles) south-west from Tuxtla Gutierrez in the state of Chiapas.
Residents there fled into the streets and have remained out of their homes in fear of possible aftershocks.
The tremor was also felt in the capital, Mexico City.
The earthquake struck at 0650 local time (1250GMT) on Tuesday.
"It was horrible. It really scared me," one resident of Tuxtla Gutierrez, Cecilia Gomez, told the Associated Press.
The quake was also felt in the states of Oaxaca, Tabasco and Puebla.
In Mexico City, some 600km away, tall buildings swayed but no damage was reported.
Just wondering how Puerto Vallarta made out in the quake. We have been trying to reach our friends who live there but the telephone appears to not be working.
Lynne Ferrie, Canada
We had about 6 aftershocks the last 3 days, the strongest one was 5.1 which to me and my neighborhood was strong, knock down few of my decorations around the house, and the dogs went crazy running everywhere, and barking, I am Salvadorian and I survived one of 9.2 in 1985 I don't like quakes at all. What causes it?
Annie Angels, El Centro, California USA
Are there any reports of earthquake damage in Guatemala from the Mexico quake today?
guspulle, houston u s
Jumped out of a shaking bed and ran out of the house along with all the other residents and neighbours. No damage. Was in San Jacinto Amilpas, a village outside Oaxaca city.
christine bayliss, oaxaca, mexico
Shortly after getting up today the house moved sideways a few times and the water in the swimming pool started to lap from side to side. For Villahermosa this was quite scary. This quake followed a smaller one, felt here Monday afternoon that caused mass evacuation of my office block.
David Pring , Villahermosa, Mexico
We are in the capital of the state of Veracruz, some 500 miles to the North of the epicentre. We rarely feel quakes here, but this morning's sent tremors throughout the city. We woke up to find our bedroom shaking.
Thomas Dunmore Rodriguez, Xalapa, Veracruz, Mexico
I am a missionary pilot with Great Commission Air. My family and I live and work in the Ixcan region just south of Chiapas. The Quake woke me up and rattled the houses in our village but it was brief caused no damage.
Robert Rice, North Quiche, Guatemala
We felt it here in Puebla which is between Mexico City and Veracruz graham Belton, a Brit living in Puebla
graham belton, puebla mexico
This time I knew it was not a lorry or a bus passing next to the house when quite strong shakes woke me up this morning. Me and my wife jumped out of bed and went quickly to the balcony. All the electricity and telecoms posts were moving from side to side and all the animals went dead quiet. We rushed downstairs however shortly after that everything stopped. Luckily there were no any aftershocks. We have not noticed any damages indoors as well as outdoors. Good experience but gives lots of adrenaline. Saludos from Mexico!
We are on the top floor of a six storey condo in Mexico City....the vertical blinds started a dance, and the wind chimes jangled...no time to leave the building which was like a Jello pudding....a very unpleasant feeling .....this has happened on at least three occasions in as many years....I went for a cold Corona for breakfst
ian symonds, mexico city....mexico
The quake was felt by some people but not by others in our city. No damage and no injuries reported.
Peter Scarratt, Puebla, Mexico