History of Syrian rebel pullouts

The agreement reached on Tuesday for Syrian rebels to withdraw from their one-time bastion of east Aleppo is the latest by opposition forces surrounded by government forces.

For much of the conflict in Syria, the government has promoted "local reconciliation" deals that have often involved the evacuation from opposition territory of civilians and rebels who have surrendered.

The government says such deals are the best way to end the conflict that began with anti-regime protests in March 2011, before spiralling into civil war.

But the opposition says they are forced into these agreements after months or years of siege and army bombardment.

The tactic has attracted international concern, with allegations that the government is pursuing a "starve or surrender" policy against opposition areas.

More than 800,000 Syrians live under siege, according to the United Nations, with most encircled by regime forces, although rebels also use the tactic.

- 'Revolution capital' Homs -

Probably the most well-known evacuation deal produced the 2014 withdrawal of rebels from the Old City of Homs after a two-year government siege.

Homs was dubbed the "capital of the revolution" after vast protests there early in the uprising.

Assad's forces later blockaded and bombarded insurgents holed up in the historic quarter.

Most were finally evacuated in May 2014 under a deal involving a major rebel coalition and regime backer Iran.

But the regime continued to besiege Waer, the last remaining opposition-held district in Homs, until a local deal was agreed in December 2015.

Over the next several months, hundreds of rebels and their families were bussed out of Waer and taken to rural areas of Homs province.

- Safe passage to Idlib -

In August 2016, all rebels and civilians from Daraya near Damascus were evacuated under a local agreement that followed a four-year government siege.

The opposition fighters and their families were given safe passage to rebel-held Idlib in the northwest, and regime troops moved back into the town, once a symbol of Syria's peaceful uprising.

In September, a further 300 Syrians living in rebel-held Moadimayet al-Sham near Damascus were evacuated under the same accord.

Opposition fighters said they were forced to accept the deal, as a blockade and constant bombardment by the army had made the humanitarian situation untenable.

- The four towns deal -

A UN-backed agreement saw hundreds of people evacuated from the government-controlled towns of Fuaa and Kafraya and rebel-held Zabadani in December 2015.

Fuaa and Kafraya, in northwestern Idlib province, are Shiite towns besieged by hardline Sunni Islamists.

And Zabadani, along with Madaya, are two rebel-held towns near Damascus that are surrounded by government forces.

The elaborate deal involving Lebanon and Turkey as transit countries has also led to humanitarian deliveries to both rebel and regime areas, most recently in September 2016.

- Aleppo rebels -

Remaining rebels in east Aleppo appear to have little leverage to force regime concessions, and even though the agreement has been reached, there is no guarantee an evacuation will go ahead.

Russia previously announced several "humanitarian corridors" that would allow safe passage for rebels and civilians out of the city, but few took advantage of them.

In October, the UN and key medical groups held days of talks to try to secure safe passage out of Aleppo for the sick and wounded, but the effort collapsed when fighting resumed.

In early November, a unilateral Russian-declared ceasefire in the city was marred by rebel fire on evacuation routes, and there was no sign that any civilians or rebels left besieged districts.