A man upset over custody of his child threatened to blow up his van a block from the White House on Tuesday, prompting a standoff with police, the FBI said.

Portions of several streets were closed, creating traffic gridlock in downtown Washington. A motorcade carrying President Bush was diverted to a different White House entrance. Bush was returning from a speech elsewhere in the city.

Debra Weierman, spokeswoman for the FBI's Washington field office, said the man claimed to have 15 gallons of gasoline. He said he would "blow it up if he doesn't get his child back," she said.

Police attempted to negotiate with the man, whose name was not disclosed. His red van has Michigan license plates.

The standoff began at about 3:30 p.m. at the corner of 15th Street and Pennsylvania Avenue, along the parade route that Bush will travel after his inauguration Thursday.

Nearby buildings were evacuated as a precaution and police moved in vehicles to block the van but continued talking to the man into the evening, said Sgt. Joe Gentile of the District of Columbia's Metropolitan Police Department.

Source: Agencies