Syrian air defenses on Sunday thwarted hostile targets in the northwestern city of Masyaf in Hama Governorate, Assad regime-linked TV reported.

Masyaf is known to be the city where the Russian air defense system S-300 is deployed.

Regime-linked media said explosions heard in Masyaf were a result of shells launched by rebel groups in the western countryside of Hama.

A cargo train was also targeted and derailed by a "terrorist" attack several hours earlier as it carried phosphate through central Syria, the regime's transport ministry said.

The train's crew suffered "various injuries" when the train came off the tracks in Homs province, spilling the loads from two cars and starting a fire, it said.

The Syrian Observatory for Human Rights also reported the incident, saying a bomb placed by "unknown people" on a stretch of track east of Palmyra had exploded as the train passed.

The blast put the train "entirely out of service," the Britain-based war monitor added.

Shortly after Syria's conflict broke out in 2011 with anti-regime protests that were brutally repressed, Western powers imposed sanctions on the regime of Bashar Assad, including a fuel embargo.

The complex war, which has since dragged in regional and world powers including regime allies Russia and Iran, has left more than 370,000 people dead and millions displaced.