A video posted on the Internet shows the graphic killings of three Russian diplomats kidnapped in Iraq, and says an Al Qaeda umbrella group has killed all four hostages.

The video, posted on an Islamic Web site the frequently airs militant messages, showed the beheading of one blindfolded man, the headless body of another in a pool of blood and the shooting of a third man.

The Mujahedeen Shura Council, an umbrella organization linking seven insurgent groups including Al Qaeda in Iraq, claimed responsibility for the executions in an accompanying statement.

CountryWatch: Iraq

"God's verdict has been carried out on the Russian diplomats ... in revenge for the torture, killing and expulsion of our brothers and sisters by the infidel Russian government," the statement said.

The video began with a verse from the Quran appearing in white letters on a black screen, and a voice reading "Those who aggress on you, you aggress on them."

One at a time, the four men appear on camera, staring ahead and speaking in Russian. Then the camera cuts to the killings.

The footage was stamped with the logo of Al Qaeda.

Four Russian embassy workers were abducted on June 3 after an attack on their car in Baghdad's Mansour neighborhood. A fifth Russian was killed in the incident.

The captives include the embassy's third secretary, Fyodor Zaitsev, and three other staffers, Rinat Agliulin, Anatoly Smirnov and Oleg Fedoseyev.