A freight train slammed into a passenger bus and dragged it down the tracks in central Mexico on Thursday, killing at least 21 people and injuring at least 10, police said. The crash happened about 9 a.m. (1500 GMT) in the city of Cuautitlan, just north of Mexico City, said Mexico State Public Safety spokesman Alberto Mena. Another department spokesman, Octavio Campos, told The Associated Press that 19 bodies had been recovered from the bus's wreckage, and that two of the 12 people initially listed as injured later died in the hospital. Mena said the crash occurred after the driver of the bus, owned by the private company Melchor Ocampo, apparently tried to beat the approaching train across the tracks. Authorities said the train was pulling 36 empty wagons at the time, and both the driver and the train conductor were detained for questioning.