The men claim to have an agreement to receive weapons, including surface- to-air missiles and rocket-propelled grenades, from underground dealers from Poland - a Nato member - the newspaper said.
The volunteers, some of whom are veterans of the Chechen war, included fighter pilots, artillery men, aircraft gunners and commandos, according to an article by Alexander Zhilin, a respected correspondent who specialises in military affairs.
Mr Zhilin said he met volunteers from Russia, Belarus and Ukraine during a recent trip to Belgrade. They said 118 volunteers arrived from the former Soviet Union last week, and were stationed at the city's central stadium, "waiting for marching orders".
He found no evidence they were mercenaries. One, whom he named as a former Russian army intelligence officer called Andrei Solopchuk, told him that if the air strikes continue "so many volunteers will come here from Russia, Ukraine, Kazakhstan, Belarus, Moldova and the Dneister region that battalions ... could be formed".
The newspaper reported that the volunteers had been welcomed by the Serbian population but - significantly - had not succeeded in their efforts to meet the Yugoslav military. Right-wing groups in Russia have been signing up volunteers to go to Yugoslavia since the conflict began more than a week ago, but yesterday's report was the first suggestion to reach Moscow that volunteers have actually arrived there.
The Russian military is still seething over its defeat in Chechnya, and the loss of the Soviet Union, and is capable of discreetly dispatching arms to the region without official approval.
President Boris Yeltsin, head of by far the largest and best armed former Soviet republic, has stated that Russia has no intention of joining the conflict, or breaking the United Nations' embargo against sending arms to Yugoslavia.
Yesterday, less than 24 hours after Russia announced plans to dispatch a warship to the region, he appeared on national television with a new initiative, calling on the Group of Eight industrial countries to convene an emergency meeting on the Yugoslav crisis. "Every lost day brings new casualties and tragedies. We must act immediately," he said.
But a political solution remains a long way off and, while the conflict continues, there is a risk to Russia that its men and weapons will be drawn into the conflict without the government knowing anything about it.