DAMASCUS, Syria — Russian warplanes have attacked the Islamic State group and other insurgents in central and northern Syria with a wave of new air strikes, Syrian and Russian military officials said Saturday as an activist group said Russia’s air raids have killed 39 civilians over the three past days. The new strikes came as residents of Syria’s central regions fear the Russians are clearing the way for a ground offensive by the government on several towns in the central province of Hama and the northwestern region of Idlib — where the Syrian army suffered major setbacks over the past months, activists said. In Damascus, an unnamed Syrian military official was quoted by state TV as saying that the “concentrated and precise” air strikes destroyed a command center in the central town of Latamneh in Hama province and targeted positions in the northwestern areas of Jisr al-Shughour and Maaret al-Numan. Since Russian President Vladimir Putin ordered the start of an air campaign against radical Islamist fighters in Syria on Wednesday, the Pentagon and other Western countries also trying to stop the advance of Islamic State fighters have accused the Kremlin of targeting their air strikes on rebel militias trying to depose Syrian President Bashar Assad. The raid came as hundreds of people fled their homes in areas near Hobeit fearing a ground offensive by government forces, activists said.