At least 105 people were killed in a powerful 7.1-magnitude earthquake that hit Mexico on Tuesday and the toll is expected to increase, officials said.In Mexico City alone, at least 30 people died and 44 buildings were reduced to rubble. Eight others were reportedly killed in the surrounding state of Mexico, 13 in the state of Puebla and 54 across the state of Morelos, the Los Angeles Times reported.The temblor caused buildings to sway violently in Mexico City, including in the historic districts of El Centro and Roma, collapsing some of them and causing huge cracks to appear on the facades of others.On Amsterdam Street, a normally tranquil road that rings a major park in the upscale neighbourhood of Condesa, a large apartment building crumbled into a pile of concrete and dust.Hundreds of residents helped a team of soldiers, police officers and firemen search the rubble for survivors.Some rescuers commandeered shopping carts from a nearby supermarket and formed a human chain to haul away rubble. Several times, a warning went up about a possible aftershock or gas leak, sending hordes of panicked people running.A video recorded from a skyscraper showed giant plumes of dust rising in the air.Police cordoned off entire blocks because of the fears that gas leaks could cause explosions. Flights into Mexico City were temporarily rerouted to other cities but the airport reopened after checks.The US Geological Survey calculated the preliminary magnitude of the earthquake at 7.1. The epicenter was about 80 miles southeast of Mexico City in the state of Puebla.It struck on the anniversary of a 1985 temblor, which killed thousands of people and devastated large parts of Mexico City -- a tragedy that President Enrique Pena Nieto had commemorated earlier in the day.