In a tape exclusively aired by Aljazeera on Sunday, members of the Army of the Victorious Sect called for an end to the "criminal project [Iraq's occupation]" before it was too late.
The video footage appeared to show the men in good health. Employed by Russian-based energy company
Interenergoservis, both Russians are known to have worked at al-Dura power plant south of Baghdad.
Iraq has been rocked by a series of foreigner kidnappings, as well as revelations of US abuse of Iraqi prisoners and persistent anti-occupation resistance.
On 13 April, television footage showed a group calling itself the Mujahidiin Brigades holding four Italian hostages. The group threatened to execute the hostages unless Italy met their demands for a withdrawal of Italian troops.
One hostage, Fabrizio Quattrocchi, was executed shortly thereafter. A video showing the beheading of US contractor Nicholas Berg was posted last week on an Islamist web site.
Canadian Muhammad Rifat was kidnapped on 8 April.
Meanwhile, several Italian soldiers were slightly hurt on Sunday during a third day of skirmishes with Shia militia around the southern Iraqi city of al-Nasiriya, 375km southeast of Baghdad.
The head of the Italian taskforce in Iraq, General Gian Marco Chiarini, said Shia fighters were trying to wrest control of the city, but that the situation had not yet spiralled out of control.
"This is not a war," Chiarini told Italy's RAI 3 news channel. He added: "There is fighting going on and the situation is extremely tense and rather complex."
"This is not a war. There is fighting going on and the situation is extremely tense and rather complex"
General Gian Marco Chiarini, Italian troops chief
The latest trouble flared on Friday as militants stormed the governor's building and then gathered around the main police station and a bridge over the Euphrates River.
The upsurge of violence has alarmed Prime Minister Silvio Berlusconi's government, which has invested a lot of political capital in its support of US operations in Iraq.
Foreign Minister Franco Frattini said on Sunday Italy had asked the United States to halt major assaults against Iraqi holy cities seen in Rome as a root cause behind the latest violence in Iraq.