A strong magnitude-6.5 earthquake rocked Mexico Saturday night, the U.S. Geological Survey said. The quake is believed to have killed at least two people, Reuters reported.

According to the USGS, the earthquake was centered about 42 kilometers (26 miles) southwest of Iguala in the state of Guerrero or 166 kilometers (103 miles) south-southwest of Mexico City.

Striking at 8:47 p.m. EST, the quake was 64.9 kilometers (40.3 miles) deep.

The USGS initially said that the quake was of magnitude 6.8, but downgraded it, first to 6.7 and then to 6.5.

Preliminary reports showed no damage or injury to anyone in the capital city, but several areas were without electricity, Mexico City Mayor Marcelo Ebrard wrote on his Twitter page.

However, emergency-services personnel told Reuters an 18-year-old man was killed when a roof collapsed in Iguala and a 25-year-old man was killed when a rock fell on a small van on the Mexico City-Acapulco highway.

The Pacific Tsunami Warning Centre said in a statement that a destructive Pacific-wide tsunami is not expected and that there was no threat to Hawaii.

Much of Mexico lies on the Pacific Ring of Fire, which is a zone of frequent earthquakes and volcanic eruptions.

In 1985, a historic earthquake of magnitude 8.0 struck off Mexico’s Pacific Coast, which was centered about 350 kilometers (217 miles) from Mexico City, killing thousands of people.