WASHINGTON -- The Washington Monument was closed for about two hours Friday after a bomb threat was called in to local police. A search turned up nothing suspicious.

The all clear was given after the U.S. Park Police evacuated the Washington Monument before 3 p.m. Friday.

Constitution and Independence avenues were closed between 15th and 17th streets during the evacuation, causing gridlock in downtown Washington, but those roads reopened later.

D.C. police received a telephone threat to the Washington Monument. Sgt. Scott Fear said D.C. police then notified U.S. Park Police.

The monument and the area of the National Mall near the monument were then evacuated. A source said that the threat had limited credibility.

Metro officials said there's a possibility that a pay phone inside the Tenleytown Metro Station was used to phone in a threat against the Washington Monument. U.S. Park Police are looking into whether a pay phone at Tenleytown was where the call originated. Metro spokeswoman Lisa Farbstein said tapes from subway station cameras are now being reviewed by transit police.

Authorities searched the area near the monument. Fear said the monument was checked for what he called "any possible explosives that may be there."

Metro officials said that buses were detoured due to the street closures. Train service was not affected.

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