Federal officials say 100 agents, analysts and other personnel have arrived in Houston in an effort to stop the flow of firearms from the United States to drug cartels in Mexico.

Kenneth Melson, the acting director of the Bureau of Alcohol, Tobacco, Firearms and Explosives, said Tuesday the agents and other support staff will spend the next four months in the bureau's Houston field division.

They'll be developing cases against people and groups trafficking firearms to Mexico.

Melson says 90 percent of the guns that Mexican authorities have seized from cartels and other criminals and given to U.S. officials to trace have come from the United States.