Russian airstrikes in Syria have killed hundreds of militants, President Vladimir Putin said Friday, October 16, as he called for a shared military effort of ex-Soviet nations to prevent possible militant incursions to Syria from Afghanistan, the Associated Press reports.

Putin told a meeting of leaders of member states of the Commonwealth of Independent States in Kazakhstan that the Russian military has achieved "impressive" results during the air campaign in Syria that began on Sept. 30.

"Dozens of control facilities and ammunition depots, hundreds of terrorists and a large number of weapons have been destroyed," he said.

Putin reaffirmed that the Russian bombing blitz against the Islamic State group and other radicals in Syria will continue "for the period of the Syrian troops' offensive operations against terrorists," but wouldn't elaborate.

He said between 5,000 and 7,000 people from Russia and other ex-Soviet nations are fighting alongside Islamic State militants.

"We can't allow them to use the experience they have just gained in Syria back home," he said.

Russian jets have flown more than 600 combat sorties since start of the air campaign, said Col.-Gen. Andrei Kartapolov of the Russian military's General Staff.

He shrugged off the U.S. claim that four of the 26 cruise missiles launched at targets in Syria by Russian navy ships from the southern part of the Caspian Sea had crashed on the Iranian territory.

Putin's comments come a day after President Barack Obama announced plans to keep about 9,800 U.S. troops in place in Afghanistan through most of next year to continue counterterrorism missions and advise Afghans who are battling a resurgent Taliban.