GUATEMALA CITY - Gunmen dressed as police officers shot dead seven men at a Guatemalan health clinic on Thursday in a brazen attempt to kill an alleged drug trafficker, who managed to escape the firefight, the government said.Interior Minister Mauricio Lopez told reporters a gang of men entered the clinic in an upper-class neighborhood of the capital looking for frequent client and alleged Guatemalan drug trafficker Jairo Orellana.When security turned the men away, the assailants opened fire with AK-47 assault rifles, killing six men thought to be Orellana's personal security and one clinic guard before speeding away in five sport utility vehicles.