A 26-year-old man pleaded guilty yesterday to phoning in fake bomb threats to authorities in the District in December and in February. The December threat prompted the closure of schools, major streets and parts of two Metrorail lines in Northeast Washington.

Jason Lewis Foster pleaded guilty in U.S. District Court in Washington to one count of making threats to kill and injure others by means of an explosive. He faces up to 10 years in prison.

U.S. District Judge Paul L. Friedman scheduled sentencing for Nov. 5.

Law enforcement authorities said that Foster called police 12 times Dec. 12 and told them that he had placed three bombs in the area of the 400 block of Oklahoma Avenue NE. Foster lived on Oklahoma Avenue.

Police found a fake bomb about 7 a.m. that day on a playground near Robert F. Kennedy Memorial Stadium. No other devices were found.

The phone calls prompted school evacuations and a partial shutdown on the Orange and Blue Metro lines, which delayed commutes for tens of thousands of riders in the District, Maryland and Virginia.

At 5:15 a.m. Feb. 20, Foster again called D.C. police to report a bomb in a vehicle parked in the 400 block of Oklahoma Avenue NE, authorities said. About a minute later, he called to say that the bomb was set to go off at 3 p.m. Police found no bomb.

Later that day, Foster phoned in three more threats, the U.S. attorney's office said.

Authorities eventually traced the calls to Foster's home phone. And on Feb. 25, the FBI's Joint Terrorism Task Force obtained a search warrant, searched his home and arrested Foster. Foster subsequently admitted phoning in the threats.

In court yesterday, Foster told Friedman that he committed the crime.

Foster's attorney could not be reached afterward to comment.