US attacks on a Baghdad hotel housing foreign journalists and on the office of an Arab television station were war crimes, the head of the international journalists' watchdog group Reporters Sans Frontieres (RSF) charged Saturday.

"Seeing an American tank firing at the Palestine Hotel and Americans hitting Al-Jazeera television, we're no longer talking professional risks. These are war crimes, " said RSF Secretary General Robert Menard.

Two journalists were killed by a tank round fired into an upper floor of Baghdad's Palestine Hotel where foreign correspondents were based, and an Al-Jazeera correspondent was killed in a separate missile attack on the Arabic news network's offices in downtown Baghdad.