The rebel Free Syrian Army, which "tactically" withdrew on Thursday from its Baba Amr bastion in Homs before a withering assault from regime forces, boasts thousands of soldiers but remains disorganised and outgunned.

Led by a defected colonel who took shelter in Turkey, Riyadh al-Asaad, the rebel group put up a fierce resistance during 27 days of relentless shelling of Baba Amr by regime forces.

But they had no firepower to answer a ferocious assault launched by ground troops on Wednesday on the neighbourhood, which had become the symbol of revolt against the regime of President Bashar al-Assad.

The rebels "have pulled out tactically in order to protect the remaining civilians," Colonel Asaad told AFP Thursday.

Asaad announced in July his defection in protest at the regime's violent repression of a protest movement that erupted mid-March, and which has now claimed more than 7,500 lives, according to the United Nations.

The group has claimed responsibility for several deadly operations against Assad's forces, particularly in the northwestern province of Idlib, near Turkey, the central city of Homs and Daraa province in the south.

In late August, the Free Syrian Army merged with the Free Officers Brigade, which was established by Colonel Hussein Harmush, who was the first army officer to announce his defection in protest at the army's brutality against unarmed civilians, siding with protesters in early June.

He succeeded in leaving Syria and establishing the Free Officers, comprising dozens of defectors, before falling back into the hands of the regime under murky circumstances.

A report by a human rights group that he was later executed has not been confirmed.

The exact number of members of the FSA remains difficult to determine but Colonel Assad told AFP in November that he had about 20,000 men. Other officers speak of up to 40,000 rebel fighters.

Most, however, have little experience in fighting, including Assad himself who previously worked in the military's IT section.

They are meanwhile facing well-trained fighting units of the Syrian army, known for their loyalty to the regime, and comprising of 140,000 to 160,000 troops, backed by powerful artillery, tanks and helicopters.

Besides the difficult task of organising disparate units scattered around the country, the Free Syrian Army lacks heavy weapons against the tanks of the regular army.

But some members of the rebel army interviewed by AFP in Syria say they expect they will soon receive anti-aircraft and anti-tank missiles from foreign sources.

It is for this reason, they believe, that the regime is trying to seal off the border with Lebanon and enforce control over Baba Amr, which had become the distribution centre for smuggled weapons.

The Syrian National Council (SNC), the main opposition grouping, has announced the creation of a "military office" to organise the supply of weapons to fighters.

"We know that some countries have expressed a desire to arm the revolutionaries. The SNC, via its military bureau, wanted to organise this flow to avoid direct arms deliveries from particular countries," SNC chief Burhan Ghalioun said in Paris.

"The SNC will be this link between those who want to help and the revolutionaries. It is out of the question that arms go into Syria in confusion."

He said some weapons had been coming in from Lebanon but that the border was now almost entirely closed and border areas mined.

"We will determine our requests, our needs for arms and we will see which country to get them from," Ghalioun said.

"This is about defending civilians, not launching a war. This is about protecting the people's peaceful revolution. That is the defensive mission given to our armed groups."

Countries, including Qatar, have already indicated their willingness to supply arms to the rebels, while Kuwait's parliament has adopted a resolution calling for arming the Syrian opposition.

Parallel to the FSA, there is also the Higher Revolutionary Council created in February by General Mustafa Al-Sheikh, the highest ranking officer to defect so far.

According to Ghalioun, both entities will fall under the control of the newly-created military office.