A federal law-enforcement building in El Paso has been evacuated after two people in the mail room were exposed to an unknown white powder.
FBI spokeswoman Andrea Simmons said the powder was found Wednesday in mail addressed to a "national public official" whose name she did not know.
The employees who came in contact with the powder were taken to a hospital as a precaution.
About 200 FBI employees and nearly 100 U.S. Drug Enforcement Administration personnel were sent home while hazardous materials crews worked to identify the substance.
Governor's offices in more than 40 states, including Texas, had received mail in December with an unknown white powder that authorities later deemed harmless.