REBELS seized an air defence facility and attacked a military airport in eastern Syria yesterday, hitting back at an air force on which President Bashar al-Assad is increasingly relying to crush his opponents, a monitoring group said.

The attacks in the eastern oil-producing Deir al-Zor province follow rebel strikes against military airports in the Aleppo and Idlib areas, near the border with Turkey.

Syria's leader, battling a 17-month-long uprising in which 20,000 people have been killed, has lost control of rural areas in the northern, eastern and southern regions and has resorted to helicopter gunships and fighter jets to subdue his foes.

The latest fighting came as Algerian diplomat Lakhdar Brahimi replaced Kofi Annan yesterday as the UN-Arab League mediator trying to end the war.

The aerial bombardment has driven fresh refugees into neighbouring countries, reviving Turkish calls for "safe zones" to be set up on Syrian territory – appeals ignored by a divided UN Security Council and Western powers reluctant to commit troops to secure such zones.

Rebels in Deir al-Zor overran an air defence building yesterday, taking at least 16 captives and seizing anti-aircraft rockets, according to the British-based Syrian Observatory for Human Rights.

An internet video posted by activists showed the officers and soldiers captured by rebel fighters, and Al Arabiya television broadcast footage of what it said were rockets and ammunition seized in the raid.

Abdulrahman said rebels had also attacked the Hamdan military airbase at Albu Kamal, close to Syria's eastern border with Iraq, but did not succeed in breaking into it.

The attacks come three days after rebels attacked the Taftanaz air base in Idlib province, where they said several helicopters were damaged. The insurgents also said they had shot down a fighter jet and a helicopter last week.

Assad's forces have made numerous air strikes on civilians in rebel-held areas, strafing towns with machine guns and bombs.

Bombardments of northern towns such as Azaz and Anadan, of which Assad lost control weeks ago, have led to thousands of residents fleeing to Turkey.

Ankara's call for safe havens inside Syria came after the UN refugee agency said the flow of Syrians into Turkey and Jordan – which already host more than 150,000 registered refugees – was rising sharply.

But a UN Security Council ministerial meeting produced nothing beyond a French plan to channel more aid to rebel areas.

Turkish government sources said Ankara would again push for agreement on safe zones inside Syria at the UN General Assembly later this month and would try to put pressure on Russia and Iran, which strongly oppose any such action.

Prime Minister Tayyip Erdogan, a former Assad ally, showed his frustration at the lack of action.

"We cannot take such a measure unless the United Nations Security Council decides in favour of it ... First a decision for the no-fly zone must be taken, then we would be able to take a step towards a buffer zone," Erdogan said in an interview on Turkish television on Friday.

"Bashar al-Assad has come to the end of his political life. At the moment, Assad is acting in Syria not as a politician, but as an element, an actor, of war," he said.

■syria