Russia has launched rocket strikes on Islamic State targets in Syria from its warships in the Caspian Sea, 1,500km (932 miles) away, Russian Defence Minister Sergei Shoigu says.
He said four warships launched 26 sea-based cruise missiles on 11 targets, destroying them.
Meanwhile, Syrian ground troops have launched an offensive under Russian air cover, Syrian officials say.
Russia denies claims that its week-long strikes mainly hit non-IS targets.
The Syrian Observatory for Human Rights reported "the most intense fighting in months" in Hama and Idlib provinces.
The clashes followed a wave of Russian air strikes in the same areas, it said.
It appears to be the first co-ordinated offensive since the air campaign by Russia - a staunch ally of Syrian President Bashar al-Assad - began on 30 September.
Russia says it is targeting "all terrorists", but at least some of its air strikes have reportedly hit civilians and Western-backed rebels.
Source: BBC News, UK.