Ciriello, who was on assignment for the Italian daily Corriere della Sera, is the first foreign journalist killed while covering the current Palestinian uprising, which began in September 2000.
The photographer died after being hit by several rounds of machine gun fire from the direction of an Israeli tank in Ramallah during Israel's ongoing military offensive in the West Bank and Gaza Strip.
Amedeo Ricucci of the Italian television station Rai Uno told CPJ that he and his cameraman were accompanying Ciriello at the time of the incident. They were trailing a group of Palestinian gunmen who were some 200 yards in front of the journalists. Ricucci said the area was quiet and was located roughly 500 yards to a half mile from a nearby refugee camp where fighting between Israelis and Palestinians was taking place.
The three journalists were standing inside a building off an alleyway, Ricucci said.
Shortly afterward, what appeared to be a tank emerged at one end of the street some 150 to 200 yards away, he said. Ciriello left the building and pointed his camera at the tank. He then came under fire without warning. Ciriello was shot six times and died of his wounds soon afterward.
There was at least one Palestinian gunman in Ciriello's vicinity at the time of the shooting, according to The Associated Press.
The Italian government has demanded a full investigation into the attack, according to the AP.
An Israeli Defense Forces (IDF) spokesman was unable to provide details about the circumstances of the shooting and claimed to have no information about the presence of journalists in Ramallah, which the IDF said was a closed military area.
The IDF added that journalists who entered the area were "endangering" themselves and claimed that it was not clear whether Ciriello's death was caused by Israeli or Palestinian gunfire.
Palestinian doctors said the rounds were fired by Israeli forces, according to press reports. Ricucci told CPJ that Ciriello's camera was in the hands of Italian authorities. The images it contained could help determine the source of the firing and the circumstances of the incident.
"It is the responsibility of all sides to ensure the safety of journalists covering this conflict, and we urge them to do so," said CPJ executive director Ann Cooper. "Whatever the circumstances of this tragic incident, Israel should provide a full accounting of what happened and bring anyone found guilty of wrongdoing to justice."
In a separate incident, an Egyptian journalist told CPJ that his car came under Israeli gunfire, also in Ramallah. Reporter Tareq Abdel Jaber of Egyptian TV said that he and his cameraman were driving on a main street in Ramallah when their car, which was clearly identified as a press vehicle, came under attack by what he described as Israeli gunfire.
There was no fighting taking place in the area at the time, Abdel Jaber said.
Bullets penetrated the car and struck his flak jacket. He was not seriously hurt. Although Abdel Jaber did not visually identify the shooter, he said the entire area was surrounded by Israeli tanks and military personnel.
According to press reports, finally, a French journalist on the West Bank was wounded in the legs today by gunfire or shrapnel. CPJ has so far been unable to identify the journalist or the circumstances of the attack.