DAMASCUS, Syria — Russian warships in the Caspian Sea fired cruise missiles Wednesday as Syrian government troops launched a ground offensive in central Syria in the first major combined air-and-ground assault since Moscow began its military campaign in the country last week.

The missiles flew nearly 930 miles over Iran and Iraq and struck Raqqa and Aleppo provinces in the north and Idlib province in the northwest, Russian officials said. The Islamic State group has strongholds in Raqqa and Aleppo, while the al-Qaida-linked Nusra Front has a strong presence in Idlib.

U.S. Defense Secretary Ash Carter said Russia was continuing to strike targets other than Islamic State militants, adding that he was concerned about the Syrian ground offensive backed by Moscow’s airpower.

Russia began airstrikes in Syria, its longtime ally, on Sept. 30. The complex war has torn apart the Mideast country since 2011.

Activists and rebels say the targets have included Western-backed fighters and other groups opposed to President Bashar Assad.

A Syrian official and activists said government troops pushed into areas in the central province of Hama and south of Idlib in the boldest multipronged attack on rebel-held areas, benefiting from the Russian air cover. The official spoke on condition of anonymity because he was not authorized to talk to the media.

The Islamic State group is not present in the areas where the ground fighting is underway.

Moscow has mainly targeted central and northwestern Syria, strategic regions that are the gateway to Assad’s strongholds in Damascus, and along the Mediterranean coast.

The offensive in central Syria and the ensuing clashes with militants, including the Nusra Front, was the first major ground fighting since the Russian campaign began.

Appearing on television with President Vladimir Putin, Russian Defense Minister Sergei Shoigu said 26 missile strikes were conducted from warships in the Caspian.

The launches marked the combat debut of the Russian Kalibr, equivalent to U.S. Tomahawk missiles.

Andrei Kartapolov of the Russian General Staff said Russia has carried out 112 airstrikes on Islamic State positions since Sept. 30.