Explosion damages San Diego courthouse

updated 12:31 a.m. ET May 5, 2008

SAN DIEGO - A suspected pipe bomb exploded at a federal courthouse in downtown San Diego, damaging the front entrance and blowing out a window, authorities said. No injuries were reported.

Few people were around the building, which is a block from nightclubs in the Gaslamp Quarter, when the powerful blast also damaged the lobby area of the Edward J. Schwartz Federal Courthouse about 1:40 a.m. Sunday, said FBI spokeswoman April Langwell.

The bomb was reported by two guards in the building, who were uninjured. About 40 agents combed the front courtyard after the area was swept for explosives. No arrests have been made.

Debris was found lodged in a window about eight stories up the AT&T building that faces the courthouse.

The evidence collected will be sent to an FBI laboratory in Virginia for analysis by bomb experts.

Authorities said that surveillance cameras outside the building may provide information, but that no cameras directly face the doorway.

Streets in the area were closed until early Sunday afternoon. The courthouse will remain closed Monday as repairs are made.

No one has claimed responsibility for the blast, authorities said, and no threats were received before the bomb was left.

More from msnbc.com RedTape: DirecTV thrives on ‘deception,’ lawsuit says Doctor's mission to save Ethiopian kids' hearts Bad Santa: Gifts that say you’re old, fat or hairy  What hit Italian prime minister? Take our weekly quiz Send your holiday pictures to troops Send us your memories and images of the past decade

MORE FROM CRIME & COURTS

Crime & courts Section Front

Facing prison, Astor's son bares private life Utah police find 2 adults, 2 kids slain at home Federal judge could face impeachment Man guilty of in-home indecent exposure Legal fees mount in Madoff liquidation Search to resume for Vt. woman shot, burned Crime & courts Section Front   Add Crime & courts headlines to your news reader: