Beirut: The Islamic State group vowed on Tuesday to attack Russia and defeat it, as Moscow announced it had intensified its air campaign against jihadists in Syria.
Meanwhile, Russian President Vladimir Putin criticised Washington for refusing to cooperate with Moscow in its Syrian campaign, which is having an increasingly dramatic effect.
"Russia will be defeated," IS spokesman Abu Mohamed al-Adnani said in a recording posted online, calling on "Muslims everywhere to launch jihad against the Russians and the Americans."
IS seeks not only to overthrow Syrian President Bashar al-Assad but is also vying with Al-Qaeda affiliate Al-Nusra Front for jihadist supremacy in the country.
Al-Nusra chief Abu Mohamed al-Jolani also threatened Moscow, saying its air war would have dire consequences.
"If the Russian army kills the people of Syria, then kill their people," he said late Monday in a call to jihadists in the Caucasus. "And if they kill our soldiers, then kill their soldiers. An eye for an eye."
"The war in Syria will make the Russians forget the horrors that they found in Afghanistan," Jolani said, referring to the disastrous Soviet attempt to subdue the country in the 1980s.
Russia said today its air force had hit 86 "terrorist" targets in Syria in the past 24 hours -- the highest one-day tally since it launched its bombing campaign on September 30.
Among them, it said, were several IS targets.
Washington and its allies -- engaged in their own air war against IS in Syria and Iraq -- accuse Moscow of targeting moderate Western-backed rebels and seeking to prop up Assad, a longtime Russian ally.
Putin hit back, criticising Washington for refusing to share intelligence with Russia and accusing it of muddled thinking.
"I think some of our partners simply have mush for brains; they do not have a clear understanding of what really happens in the country and what goals they are seeking to achieve," he said.
Ironically, the IS's Adnani said the United States is weak and is using Russia and Assad's other ally Iran to strengthen its position in Syria, claiming Washington is willing "to forge an alliance with the devil".