Honduran police say Mexico has extradited an alleged gang member suspected in 43 killings, including 28 in a bus massacre.
Police chief Filiberto Martinez says Rodolfo Humberto Salinas was flown to Honduras on Saturday night.
Interpol has said Salinas is wanted in connection with 40 killings in Honduras and three in the United States.
Mexican police have said Salinas was among 10 gang members who shot up a bus full of Christmas shoppers and commuters on Dec. 23, 2004, in the northern city of San Pedro Sula. Officials said at the time the attack was apparently revenge for a government crackdown on gang operations.
Salinas has also been linked to the 2007 shooting death of President Manuel Zelaya's ex-bodyguard.