President Bush's spokesman says it is absurd to suggest U.S. troops would knowingly target civilians in Iraq. The comments came as an Italian security agent, killed at a Baghdad checkpoint, was given a state funeral in Rome.

The agent helped obtain the release of an Italian journalist who had been held hostage for a month in Iraq.

They were on their way to Baghdad airport when the shooting occurred. Accounts of what happened vary, and an investigation is underway. But the former hostage - a reporter for the communist daily Il Manifesto - has suggested U.S. troops opened fire because Italy may have paid a ransom for her release.

When asked about her comments, White House Spokesman Scott McClellan said the notion that U.S. forces would knowingly fire on innocent civilians is absurd. He said the highway to Baghdad airport is one of the most dangerous roads in Iraq.

The coffin of late Italian intelligence officer Nicola Calipari is carried during his state funeral in Rome

"It is a road where suicide bombers have carried out attacks," said Scott McClellan. "It is a road where regime elements have fired on coalition forces."

He said American troops serving there are working in a combat zone, and, sometimes, have to make split second decisions.

"They go out of their way to protect civilians and avoid civilian casualties," he said. "And we are cooperating closely with Italian authorities on the investigation."

The White House spokesman said it is important for the investigation to be full and complete. He made clear the White House believes no one should jump to conclusions, until all the facts are in.