MOSCOW (AP) — The latest developments as Russia and other nations counter Islamic State militants in Syria. All times local:

5:00 p.m.

Pentagon's press secretary says Defense Secretary Ash Carter has instructed his staff to talk to Russian officials about how to keep each other's air operations in Syria from colliding or getting in each other's way.

Peter Cook said it was not yet clear when these talks would start or who would participate.

Russia's defense ministry earlier Tuesday said its jets have started carrying out airstrikes on Islamic State group positions in Syria.

A U.S. led coalition has been targeting IS militants in Syria and Iraq since last year.

Russia and the U.S. are at odds over the Russian involvement because Washington has said Syrian President Bashar Assad, who is a key ally of Moscow, must be removed from power.

4:20 p.m.

Russia's defense ministry says its jets are carrying out airstrikes on Islamic State positions in Syria.

The ministry spokesman Igor Konashenkov told Russian news agencies on Wednesday that Russian jets are carrying out targeted airstrikes on the positions, vehicles and warehouses that Russia believes belong to IS militants.

Earlier Wednesday, Russia's upper chamber of parliament gave the green light to President Vladimir Putin's request to use Russian forces in Syria. A Kremlin official said the move was to protect Russia's national security, since at least 2,400 Russians have gone to fight in Syria or Iraq.

Syrian President Bashar Assad is a key ally of Moscow.