MEXICO CITY >> A strong earthquake struck a sparsely populated area in the mountains of western Mexico today, and caused tall buildings to sway more than 200 miles away in Mexico City. People evacuated some buildings in the capital, but the city government said helicopter flights had detected no signs of damage.

Authorities in Michoacan state, where the tremor was centered, also had no immediate reports of damage.

The Pacific Tsunami Warning Center in Ewa Beach issued a bulletin saying that the quake is not expected to generate a Pacific-wide tsunami, but that earthquakes of this size can cause destructive local tsunamis. PTWC said officials in the region near the quake should be aware of this possibility and take appropriate action.

The U.S. Geological Survey reported a preliminary reading of 7.0 magnitude for the quake but later downgraded it to a 6.5 magnitude. It struck at 3:55 p.m. local time (12:55 p.m. in Hawaii) and was centered in the sparsely populated mountainous area in Mexico’s Michoacan state, 238 miles west-southwest of Mexico City and about 209 miles west-northwest of Acapulco.

A quake of that magnitude is considered a major earthquake, but this one hit about 41 mile below the surface and a tremor’s power to cause damage is often dissipated when it is so deep.

Manuael Ortiz Rosete, the Michoacan state civil protection director, said no damage had been reported major cities and coastal communities of the state.