(CNN) -- A powerful earthquake hit Wednesday off the coast of Guatemala, killing at least three people, officials said.

About 100 people were reported missing, 15 were reported trapped under rubble and the death toll could rise, President Otto Perez Molina said, citing unconfirmed preliminary reports.

"These are preliminary statistics, because this only happened three hours ago. We have not confirmed them," Perez Molina told reporters Wednesday afternoon.

Unconfirmed preliminary reports indicate up to 15 people may been killed, Perez Molina said.

The 7.4-magnitude quake was felt throughout Central America and as far north as Mexico City.

iReport: Video from the quake

"This is the largest earthquake that we have had since the earthquake in 1976," the Guatemalan president said. "Fortunately, the damage that we have is not at the same level."

There were reports of homes and schools destroyed in western Guatemala, the country`s president, Otto Perez Molina, told CNN en Español.

The earthquake was centered about 15 miles from the Guatemalan coastal city of Champerico, at a depth of 26 miles.

In Guatemala, many people fled buildings when the tremor first hit.

Some 125,000 people were without power in Guatemala because of the quake, Perez Molina said.

The president said he had heard reports of some deaths, but declined to confirm any fatalities until his government collects more information.

It was fortunate that the school year in Guatemala had recently come to end, so that no children were inside the school buildings that were damaged, Perez Molina said.

Fearing powerful aftershocks, the government issued a "red alert" that warns people to take precautions, such as evacuating tall buildings. The alert stretches along the country`s entire Pacific coast.