MEXICO CITY, Oct 5 (Reuters) - Mexico will file a new lawsuit in the United States seeking responsibility for cross-border gun flows after a U.S. judge last week dismissed a separate $10 billion lawsuit against U.S. gun manufacturers, Mexico's foreign minister said on Wednesday.Mexico's foreign ministry last week said it would appeal the Sept. 30 decision of a federal judge in Boston to dismiss the lawsuit Mexico filed last year seeking $10 billion in damages from U.S. gun companies, including Smith & Wesson Brands Inc (SWBI.O) and Sturm, Ruger & Co (RGR.N).Register now for FREE unlimited access to Reuters.comMexico had accused the companies of reckless business practices that enabled the flow of guns to Mexico, undermining local law and leading to thousands of deaths."You have to start establishing criminal responsibilities because the companies that are selling these weapons in these counties (in Arizona), which are very few, of course they know where those weapons are going," he added, but did not specify which companies he was referring to.On Sept. 30, Judge F. Dennis Saylor of the U.S. District Court for the District of Massachusetts threw out Mexico's original lawsuit, saying U.S. law "unequivocally" bars lawsuits seeking to hold gun manufacturers responsible when people use guns for their intended purpose."