MEXICO CITY — A strong tremor lasting about 25 seconds struck Mexico's capital Tuesday, shaking loose debris from last month's killer earthquakes and jangling nerves still tense from the earlier ordeal.
The quake, registering 5.5 on the Richter scale, was considered yet another aftershock of the Sept. 19-20 earthquakes that killed at least 7,000 people. It struck at 9:02 a.m. and was felt as far away as Guatemala.
The only injuries reported were those to 10 people suffering from what the Red Cross called "nervous crisis" who panicked and ran away from a building that was badly damaged in last month's quakes. They sustained bruises when they fell while running.
The Sept. 19 earthquake, measuring 8.1 on the Richter scale, collapsed or severely damaged about 3,000 buildings. It was followed the next day by a 7.5 quake. Since then, dozens of lesser tremors have hit the capital without causing damage.
During Tuesday's aftershock, which was stronger than most, lamps swayed and ceiling tiles fell in some already damaged buildings. Clouds of dusts billowed from ruins. Debris fell from buildings damaged earlier.
The government news agency Notimex said the National Seismological Laboratory recorded the quake at 5.7 on the Richter scale, with its epicenter 235 miles west of the capital in the Pacific off Michoacan state.
The U.S. Geological Survey's National Earthquake Information Center in Golden, Colo., said the quake had a magnitude of 5.5.
Mexico City Mayor Ramon Aguirre, in the first of what the government said will be a series of reports on the devastation, said Monday night that 720,000 tons of rubble have been carted from the city so far. He said food has been provided to more than 50,000 homeless people in temporary shelters and camps.
Mexican President Miguel de la Madrid has said the damage in September was so vast that it will take years for reconstruction to be completed.
Most government officials now agree on a figure of 7,000 deaths from the September quakes.
The U.N. Economic Commission for Latin America, in what has been called here the most detailed report yet on the devastation, said last week that 6,000 people were killed and 2,000 were missing and presumed dead.
The commission estimated property damage at $4 billion and said 150,000 people had to leave their homes.