The Washington Monument was evacuated and the streets around it blocked off because of a bomb threat, a law enforcement official said today.
People were evacuated from the 555-foot (170 metres) obelisk on the National Mall because of the threat, the official said.
The threat was made by telephone at 2:24 p.m. EDT (1824 GMT), Sgt. Scott Fear of the National Park Police said on CNN television.
About an hour after the threat, Fear said officers were doing a thorough check of the area around the monument, which is less than a mile (1.6 km) from the White House, but had not found anything suspicious.
"It's obviously an ongoing investigation," he said. "Once we finish that check, we should be able to reopen the Washington Monument."
Carrie Edler, 42, who was visiting from Los Angeles, said after the evacuation: "I think it's sad, it's pathetic, it's becoming an every day occurrence. It's becoming a way of life though."