The first Syrian rebels are due to withdraw from areas oh Homs after agreeing a ceasefire deal with government forces who had surrounded them.

According to activists inside Syria's third largest city, the first of about 1,000 fighters would withdraw from the Old City on Saturday to countryside to the north of the city.

The withdrawal is expected to be supervised by a UN delegation and the government reconciliation committee.

Syrian Red Crescent ambulances will also evacuate the injured from the Old City area under the terms of the 48-hour deal, and rebels will release an Iranian officer they are holding prisoner.

While Saturday's deal will leave the city in effective control of government forces, there are reports of fighters living among the population in the densely populated al-Waer neighbourhood.

Homs is known as the 'capital of the revolution' for street protests against the government of President Bashar al-Assad during the early days of the Syrian uprising in 2011.

Activists inside the city told Al Jazeera they blame a punishing siege and the lack of international assistance for the rebel agreement to withdraw.

"It is impossible to take the city back but we were so weak. We were hungry. We couldn't even walk 100 metres. I used to weigh 73kg, now I weigh 53kg", said an unidentified activist from Homs.

Rebel-held areas were surrounded and face fierce bombardment since the government launched a campaign to take the city in 2012.

The city is strategically important as it connects government strongholds along the western coast with the capital, Damascus.

"The regime is concentrating on retaking strategic territory, it is part of their plan to partition the country" said Khaled el-Khoja, of the Syrian National Council, an opposition block in exile.

In February, a deal reached by the opposition and the Syrian government at peace talks in Geneva allowed most civilians to leave rebel-held areas of Homs.