Assad forces pound Syrian cities

Damascus and Syria's second biggest city, Aleppo, came under shell fire from government forces battling a growing insurgency against president Bashar al-Assad today, opposition activists in the area said.

One of the most senior figures to defect from Dr Assad's inner circle, Brigadier General Manaf Tlas, put himself forward as someone who could help unite the fragmented opposition inside and outside Syria on a plan for a transfer of power.

Turkey laid down a marker by threatening to act against "terrorists" in northern Syria, a reference to Kurdish militants linked with the Kurdistan People's Party (PKK).

Turkish prime minister Tayyip Erdogan said he would strike against Kurdish militants in Syria if need be, mirroring Ankara's policy of attacking PKK bases in northern Iraq used for the group's long-running armed struggle in southeast Turkey.Turkey, a former friend of Dr Assad and now one of his severest critics, closed its border posts with Syria on Wednesday to all traffic except Syrian refugees.

A bomb attack that killed four of Dr Assad's closest lieutenants in Damascus last week and the surge of fighting there and in Aleppo prompted predictions among the 46-year-old president's enemies that his time in power was nearly over. Dr Assad himself has not spoken in public since the July 18th bombing, although he has appeared at formal televised events.

Nevertheless, his forces have hit back hard, driving rebels out of most of Damascus, where opposition sources report executions of insurgents, and then counter-attacking in Aleppo, using helicopter gunships backed by combat aircraft.

Residents in the capital reported a shell landing in southern districts every minute this morning. Helicopters attacked Hajar al-Aswad, one of the last rebel-held districts in the city after days of street fighting, activists said.Rebels said they had destroyed two Syrian army tanks.

"The Assad forces are trying to storm Hajar al-Aswad from more than one front. The (rebel) Furqan Brigade is engaging with them.

There is a fierce battle," activist Mansour Abdallah said. The army has sent reinforcements to Aleppo, determined to keep control of Syria's biggest city and commercial capital.

Fierce clashes raged there overnight, and one activist said rebels now controlled half the city, a claim that could not be independently verified, like others made by both sides. "There was shelling this morning on the Salaheddine and

Mashhad districts," said Aleppo activist Abu Hisham. "Now it has stopped, but helicopters are buzzing overhead." According to the opposition Syrian Observatory for Human Rights, the army also shelled three districts in the central city of Homs, scene of some of the worst violence of a revolt in which dissidents say more than 18,000 people have been killed.