(Updates with all clear given) WASHINGTON, July 25 (Reuters) - Two U.S. Capitol office buildings were briefly evacuated on Wednesday because of a fire alarm and the smell of smoke, authorities said. A number of fire trucks were summoned to the Hart and Dirksen Senate office buildings, but there was no immediate word on the cause for the alarm. Within minutes, congressional staffers were permitted to return after authorities gave an all clear signal. Police halted traffic on the street outside the two buildings, located across the street from the Capitol where the Senate and House of Representatives were both in session. A spokeswoman for Capitol Police said initial findings suggested the source of the smoke may have been an electrical problem.
