A civil defence member walks on the rubble of a damaged building next to a site hit by what activists said were airstrikes carried out by the Russian air force at Ehsim town in the southern countryside of Idlib, Syria.

Agencies/Beirut

Air strikes by suspected Russian jets hit targets around the town of Talbiseh in western Syria on Sunday, residents and a group which monitors the civil war in Syria said, a day after Russia promised to step up its air campaign.

Ambulances rushed wounded people to hospital in Talbiseh, north of the city of Homs, and one resident said at least five bodies had been recovered from the western part of the town.

"So far there are seven or six raids in the town," said Abdul Ghafar al Dweik, a former government employee and volunteer rescue worker.

He said he believed the raid was carried out by Russian jets. "They come suddenly... With the Syrian planes, we would get a warning but now all of a sudden we see it over our heads," he said.

The Syrian Observatory for Human Rights, which monitors Syria's four-year-old civil war through a network of sources, said Russian planes struck on Sunday in Homs province and also in neighbouring Hama.

Russia launched air strikes in Syria on Wednesday, saying they targeted the hardline Islamic State militants who control large parts of eastern Syria and western Iraq. But some of the areas it has struck have little or no Islamic State presence.

Several rebel groups around Talbiseh operate under the umbrella of the Free Syrian Army, and some have received military support from Western and Gulf Arab states that oppose President Bashar al-Assad.

The air strikes in Hama targeted a region in the east of the province controlled by Islamic State fighters, the Observatory said.

'Moderate opposition'

A senior Russian military officer said on Saturday Russian jets based in western Syria had carried out more than 60 sorties in 72 hours. "We will not only continue strikes... We will also increase their intensity," said Andrei Kartapolov from the Russian army General Staff.

President Vladimir Putin's spokesman said that Russia's Western partners had failed to explain the term "moderate opposition".

Putin, who met the leaders of France and Germany in Paris on Friday, had "expressed a lively interest in the subject and asked what the difference between the moderate opposition and the immoderate opposition is," Dmitry Peskov said on television late on Saturday.

"So far, no one really has managed to explain what the moderate opposition is."

An apparent US air strike on an Afghan hospital that killed 19 people on Saturday is also expected to play into the Kremlin's hands.

US President Barack Obama called Russia's intervention a "recipe for disaster" but pledged Washington would not be drawn into a proxy war.