ADELAIDE, Australia (AP) _ A package bomb exploded in a mail room of the federal anti-crime and corruption agency Wednesday, killing a police officer and injuring at least five people.

Police evacuated people from the area after officers found a second, unexploded bomb in the 12-story building.

The officer killed had been working in the top-floor mail room of the National Crime Authority, NCA spokeswoman Barbara Sharp said.

Another officer in the regional office lost an arm and was burned over 40 percent of his body, police said.

The blast blew out windows and showered glass on the street below.

No motive for the bombing was apparent and no warning or threat was received beforehand, police said. They said no one on the street was hurt.