One entrance to The San Diego Union-Tribune was closed Wednesday after a large envelope that authorities say contained a powdery substance labeled "anthrax" was opened in the newsroom. Officials at the Sacramento NBC affiliate KCRA-TV claimed they also received a similar envelope.

San Diego City Fire Department spokesman Maurice Luque said a hazardous materials team examined the package that was opened by a news assistant. Investigators determined the package did not contain any threat. No one was evacuated or hurt.

Luque said the powdery substance was attached to a CD containing a picture of former Secretary of State Colin Powell. Also inside was a small packet, like a sugar packet. Luque said the word anthrax was scribbled inside. Members of a hazardous materials team, all wearing full protective suits, went into the building to test the package. The Associated Press office in San Diego is in the building.

Investigators said many of the mailings had the same fictitious Sacramento return address. So far, all of the powder in the packages has tested negative, said FBI agent Darrell Foxworth in San Diego. Investigators wouldn't say what was on the CD. Foxworth said officials don't know who is sending the packages.

The packages the agency has identified so far were sent to the Union-Tribune, the Charlotte Observer in North Carolina, two Sacramento television stations and the office of Rep. George Radanovich in Modesto, said FBI agent Steve Dupre in Sacramento.

KCRA reported that the package containing white powder that arrived there was 10-by-6-inches. The powder packet was taped across the hole in the middle of the Powell CD and had a typewritten placard reading "ANTHRAX Shock & Awe Terror" pasted to the packet.

Anthrax mailed to congressional offices and others in 2001 killed five people and sickened 17.