Last Updated Oct 7, 2015 8:51 AM EDT
ISTANBUL -- Syria said Wednesday that government troops had launched a ground assault backed by intense Russian airstrikes and, for the first time, possibly Russian warships firing from offshore, targeting opposition forces.
Russian Defense Minister Sergei Shoigu said in Moscow that warships were targeting militant from the Islamic State of Iraq and Syria (ISIS), but there was no immediate indication as to if or where artillery from Russian vessels was already landing in Syria. Shoigu said the warships fired 26 missiles at ISIS targets from the Caspian Sea.
On the ground, however, the fighting appeared to have begun in earnest.
A Syrian military officer told CBS News' George Baghdadi the army had made "steady progress" in the northern provinces of Hama and Idlib in its first ground offensive carried out under the cover of Russian airstrikes.
"In the early morning, the ground operation started in the provinces of Hama and Idlib on different routes under heavy air raids from our Russian friends," the officer told CBS News on condition of anonymity.
The way the fighting was described online by activists and opposition groups also suggested it an organized offensive in the geographic triangle formed by Hama, Idlib and Latakia, the Mediterranean coastal city where Russian forces are based.
Jaish al-Fateh, a coalition of Islamic extremist opposition groups led by the al Qaeda affiliate in Syria, al-Nusra, said it was the most intense fighting with the Syrian army to date, but claimed to have taken an upper hand against the Syrian troops in northern Hama.
Russian airstrikes have pounded Syria for a week. Russia joined the more-than-four-year war saying it would target ISIS, but CBS News correspondent Holly Williams says many of the locations Moscow says it has hit are not in ISIS-controlled areas.
ISIS has little to no presence in Idlib, nor in the areas of Hama that have been targeted to date by the Russian airstrikes or the apparent Syrian ground offensive.
The U.S. says what Moscow is really doing with its warplanes and helicopter gunships is propping up the Syrian regime by attacking its opponents, including some groups linked to al Qaeda, but also moderate rebels who are supported by America.
A Syrian monitoring group says Russian airstrikes are killing dozens of civilians. As if to refute that claim, Russia released drone video which it says shows the military carefully tracking -- but not targeting -- ISIS vehicles as they drive through a civilian area and park beside a mosque.
Russian media also broadcast video showing a commander in an operations nerve-center pointing out on a monitor what he claimed were two accurate hits on ISIS ammunition depots.
Meanwhile, Turkey, Syria's neighbor and a NATO member and key U.S. ally, says Russian warplanes have twice violated its airspace.
NATO chief Jens Stoltenberg called on Russia to avoid escalating tensions.
"This is exactly what we were afraid of, that incidents, accidents may create dangerous situations," he said of the apparent airspace violations, which the U.S. says did not appear to be accidental as the Russians claim.