US Immigration Agent Killed in Mexico; Another Wounded They were shot by unknown assailants on highway By Newser Editors and Wire Services Posted Feb 15, 2011 5:30 PM CST Updated Feb 15, 2011 7:10 PM CST 34 comments Comments File photo of the US embassy in Mexico City. (AP Photo/Marco Ugarte) (Newser) – A US Immigration and Customs Enforcement agent was killed and another wounded in the line of duty today while driving through northern Mexico, a Mexican official said. The two agents were driving in the northern state of San Luis Potosi when they were stopped at what appeared to be a military checkpoint, said the official. After they stopped, someone opened fire on them. The agents, who were assigned to the ICE attache office in Mexico's capital, were attacked between Mexico City and the northern city of Monterrey, according an ICE statement. Though Mexico is seeing record rates of violence from warring drug cartels and a crackdown on organized crime, it is rare for US officials to be attacked.