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powerful earthquake jolted Mexico City on Tuesday, seriously damaging buildings and sending people fleeing into the streets on the anniversary of a 1985 quake that did major damage to the capital.

Local television stations broadcast images of collapsed facades and streets filled with rubble.

The extent of damage and injuries was not immediately clear.

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The U.S. Geological Survey calculated its preliminary magnitude at 7.1. The epicenter was about 93 miles southeast of Mexico City in the state of Puebla.

Pictures fell from walls, and objects were shaken off flat surfaces. Some people dived for cover under desks.

Earlier in the day, buildings across the city held preparation drills on the anniversary of the 1985 quake.