Russian president says rebellions could empower fanatics, break up states and "spread extremism in the future".
Last Modified: 22 Feb 2011 16:04 GMT
Dmitry Medvedev's comments on Tuesday contrasted with those of Western leaders, who have largely expressed sympathy with pro-democracy protesters in North Africa and the Middle East.
"The situation is tough. We could be talking about the disintegration of large, densely-populated states, talking about them breaking up into little pieces," he said in comments broadcast on state television.
"These are not simple states and it is highly probable that there will be difficult events, including fanatics coming to power.
"This will mean fires for years and the spread of extremism in the future. We need to look this straight in the eyes."
Medvedev spoke at a security meeting in Vladikavkaz, a city in the heart of the North Caucasus, where Russian forces are fighting a predominantly Muslim separatist movement.
He added that rebellions occuring in the Arab world could have a direct effect on Russia, but that attempts to repeat unrest in his country would be quashed.
"They have prepared such a scenario for us before, and now more than ever they will try and realise it. In any case, this scenario won't succeed," he said.
"Those who want blood can drown in their own blood."
Russia has crushed separatists in two wars in Chechnya in the past 15 years, and continues to battle rebels in the predominantly Muslim Caucasus region, who have claimed responsibility for a series of deadly attacks in Moscow.
The president had taken a guarded line on the historic convulsions shaking the Arab world, urging against violence but failing to show much enthusiasm over the fall of strongmen leaders such as Hosni Mubarak, the Egyptian president and Tunisia's Zine al-Abidine Ben Ali.
Protests that started in Tunisia in December 2010 have since spread to Algeria, Bahrain, Egypt, Morocco, Libya, Iran, Sudan and Yemen.
Medvedev's comments contrast with those of the European Union a day earlier, which said it "deplores the violence" and "repression" against pro-democracy protesters in Libya.