Russia has conducted its first airstrike in Syria, near the city of Homs, a senior U.S. official told CNN Wednesday, September 30, CNN news reports.

The Russians told the United States that they should not fly U.S. warplanes in Syria, but gaveno geographical information about where they planned to strike. The senior official said U.S. missions are continuing as normal.

The upper house of the Russian parliament has given President Vladimir Putin approval to use the Russian air force in Syria, according to state media.

"The Federation Council unanimously supported the President's request -- 162 votes in favor of granting permission," Kremlin Chief of Staff Sergey Ivanov said, according to ITAR-Tass.

The vote came after a request by Syrian President Bashar al-Assad for military assistance in fighting ISIS, Ivanov said. Four Russian Su-34 Fullback fighter jets are now at the Latakia air base in Syria, and more than 600 Russian troops are in place.

Pentagon spokesman Peter Cook told reporters Tuesday that Secretary of Defense Ash Carter directed his staff to "open lines of communication with Russia on de-confliction."