Rebels near Syria's central city of Hama are being pounded with bombs and shells as the regime wages a fierce assault to reverse losses in rural areas.
Explosions in villages about 25km northwest of Hama had triggered an exodus of hundreds of residents in cars, or on motorbikes or tractors, AFP reporters said.
"We had to flee because of the shelling," a 60-year-old woman, Fatma al-Omar, said as she sheltered in an olive grove with about two dozen women and children.
Sunni refugees have been fleeing north, into territory controlled by the rebel Free Syrian Army (FSA).
Their Alawite neighbours have escaped to regime-controlled areas: to Hama, or west to the coastal provinces of Latakia and Tartus.
Russian-made aircraft dropped at least three bombs in the area.
An ad-hoc field hospital was set up in one field.
"We've treated around 30 to 35 people in the past two days, all of them civilians hurt in their homes by the regime's bombs," a doctor, Wael Mahmud, said.
In Kurnaz, rebel fighters took up defensive positions against Syrian army tanks firing shells at them.
"This area is a red line for the regime. There are many Alawites in this area so the regime is fighting very hard to take it back," said the regional rebel commander, a former army special forces colonel who goes by the name Abu Hamza.
His forces had taken Kurnaz and the area around it one month ago but were now likely to lose it.
"Our men are good fighters but our only problem is the lack of ammunition," he said.
Hama is seen as one of Syria's strategic cities in the war.
Located about halfway along a highway linking the capital Damascus in the south to Aleppo in the north, it is home to a mixed population of Alawites - the Shi'ite offshoot to which President Bashar al-Assad's family belongs - as well as Sunnis and Christians.
The regime is determined to keep control of it and to oust the rebels who lack the means to dislodge Assad's army from cities.
Abu Hamza blamed the West for not following through their rhetoric supporting Syria's armed opposition and that had provided an opportunity for the Al-Nusra Front, an Islamist fighting force.
The US deems Al-Nusra as "terrorist" organisation for its links to the al-Qaeda franchise in Iraq.
Hamza said the group was welcome because "they came to help the Syrian people, unlike the international community".