Syria conflict: Army launches offensive on Homs enclave
Syrian government forces, backed by Russian air strikes, have launched an offensive in the province of Homs.
Activists said the assault on a rebel enclave north of the city of Homs began early on Thursday and was preceded by intense bombardment.
Casualties were reported in the towns of Teir Maaleh, Talbiseh and Ghantu.
The Syrian military and its allies have launched a number of ground offensives on rebel-held areas since Russia launched an air campaign two weeks ago.
Russia says it is targeting "terrorists", primarily jihadist militants from Islamic State (IS), but many strikes have reportedly hit civilians and Western-backed rebels.
One opposition activist told the BBC there was a series of air strikes before dawn on Thursday on towns and villages just north of the city of Homs, followed by a ground assault by the Syrian army.
"Shells were raining on civilian homes," Homs-based activist Bebars al-Talawy told the Associated Press. "The air raids even shook the city of Homs" several miles away from the front lines, he said.
Mr Talawy said the government was seeking to open the motorway between Homs and Hama, to the north.
The Syrian state news agency, Sana, cited a military source as saying that a major operation against "terrorist organisations" was taking place in the Homs countryside.
The source said troops had gained control of the village of Khalidiya, near the suburb of Dar al-Kabireh, and destroyed two "terrorist operations rooms" in Talbiseh and Teir Maaleh, to the north.
The Syrian Observatory for Human Rights, a UK-based monitoring group, said Russian warplanes had carried out at least 15 air strikes on Talbiseh and nearby areas, killing 10 people, including six rebels.
The Local Co-ordination Committees (LCC), an opposition activist network, said 17 people had died when Russian aircraft bombed a shelter for civilians in Ghantu. It also reported deaths in Teir Maaleh and in Dar al-Kabireh.
The offensive was launched as a senior Iranian official said Tehran would consider sending ground forces to Syria if the government in Damascus asked.
"If Syria makes a request, we will study the request and make a decision," said Alaeddin Boroujerdi, chairman of the Iranian parliament's national security and foreign policy committee, during a visit to Damascus.
"What's important is that Iran is serious about the fight against terrorism," he added. "We have supplied aid and weapons and sent advisers to Syria and Iraq."
There are unconfirmed reports that hundreds of Iranian troops have arrived in Syria to join assaults on rebel positions in northern and central Syria by government forces and fighters from the Lebanese Shia Islamist movement, Hezbollah.
A regional official told AP on Wednesday that in the past two weeks, some 1,500 Iranian military personnel had flown to Damascus airport and then been transported to a military base in the coastal province of Latakia, adding that Hezbollah was also sending reinforcements.
Iran, a staunch ally of President Bashar al-Assad, has long acknowledged sending military advisers to Syria, but has denied the presence of any ground forces.