Syria's Bashar Assad regime and moderate opposition forces reportedly agreed on a cease-fire and evacuation deal for an area in the northern countryside of Homs province.

"The Assad regime and Russian forces will enter the region and opposition fighters will surrender all heavy weapons. Those who do not want to stay in the region will be allowed a safe exit to opposition-held areas in the north," the opposition forces said on Telegram, an instant messaging app.

Earlier on Wednesday, Russia turned down a proposal by Syrian opposition groups for a cease-fire in the countryside.

The proposal, which was made at a Tuesday meeting between opposition representatives and Russian officials in Homs, reportedly called for a cease-fire and the reopening of the region's main thoroughfares.

The enclave, the most populous zone still under siege in Syria, has seen heavy fighting and bombing in recent days. It includes the towns of Houla, Rastan and Talbiseh and surrounding villages located near a main highway between the cities of Homs and Hama.

The Assad regime is regaining control of opposition-held areas around the capital Damascus through army offensives and such local agreements with support from Russia and Iran, the main backers of the regime.

Last week, a minister from the regime said the enclave north of Homs city was the army's next target after retaking all of the insurgent territory around the capital.

Syria has been locked in a vicious civil war since early 2011 when the Assad regime cracked down on pro-democracy protests, which erupted as part of the Arab Spring uprisings, with unexpected ferocity. Since then, more than a quarter of a million people have been killed and more than 10 million displaced across the war-battered country, according to United Nations figures.