BAGHDAD, Iraq — Al-Qaida's arm in Iraq released a video yesterday showing its militants lining up five captured Iraqi security officers and executing them in the street, the latest move in a campaign to intimidate Iraqis and target those who collaborate with U.S.-led forces.

A statement posted on an Islamic Web site along with the video denounces the five security officers as "American dogs" and warns other Iraqis they would meet the same fate if they join the security forces. In the video, the five men are seen lined up, their hands bound behind their backs, and shot in the back on a street in front of passers-by.

The video and statement — issued by al-Qaida in Iraq, the group led by Jordanian militant Abu Musab al-Zarqawi — did not say where the executions took place, but separate photos of the executions indicated they occurred in the insurgent stronghold of Ramadi, west of Baghdad, on Dec. 26.

Guerrillas have proven increasingly adept at managing the Internet as part of their propaganda campaign against the United States and the Iraqi government of Prime Minister Ayad Allawi, posting technically proficient footage of attacks on convoys and military bases, as well as executions of members of the Iraqi security forces or government officials.

The U.S. military and the interim government in Baghdad want the Iraqi police and national-guard troops to provide security for the national legislative election scheduled Jan. 30, and mass desertions from those forces could scuttle such plans.

In the footage, one of the prisoners identified himself as Lt. Bashar Latif Jassim and said his mission was to "prevent terrorists from entering Iraq." When asked by one his captors — who did not appear on camera — who the terrorists are, Jassim said: "Those who sabotage the country."

The five prisoners, wearing civilian clothes, were shown sitting on the ground with five masked gunmen behind them, one reading a statement. A banner emblazoned "al-Qaida in Iraq" hung in the background.

The video then showed the execution. After the men fell to the ground, the gunmen kicked them to see who was still alive, then pumped more bullets into the bodies.

People and cars are visible in the video, passing by during the shooting, and some even stop to watch.