Some of the fiercest fighting seen since the start of the conflict in Syria raged on the outskirts of Damascus yesterday as better trained and equipped rebels attacked elite forces loyal to the regime.
The increase in violence came as Turkey's Prime Minister, Recep Tayyip Erdogan, warned that he would order his troops to attack Syrian army units if they dared to approach the countries' 550-mile shared border.
"Turkey is not a kind of country whose borders and hostility can be tested," Mr Erdogan told his parliament in Ankara. The threat came after Syria admitted shooting down a Turkish F-4 Phantom jet last Friday, which Turkey claimed was in international airspace after briefly violating Syrian territory.
Describing the Syrian regime as presenting a "clear and present" threat to Turkish security, Mr Erdogan announced a change in the rules of engagement for the country's military. Claiming that Syrian helicopters had recently violated Turkish airspace, he said that any future infringement would be met with military action.
The Syrian President Bashar al-Assad spoke in equally strong terms yesterday, claiming his country was in a state of war and ordering his newly appointed government to direct all its efforts towards vanquishing the uprising against him.
"We live in a real state of war from all angles," Mr Assad told a cabinet he appointed yesterday. "When we are in a war, all policies and all sides and all sectors need to be directed at winning this war."
Mr Assad dismissed the arguments of Western countries that have been calling for him to step aside. The West "takes and never gives and this has been proven at every stage," he said.
Meanwhile, Turkish media later reported that 15 Turkish military vehicles, including tanks and long-range guns, were being sent to reinforce the border. It is being suggested that the move takes Ankara closer to creating a "buffer zone" inside Syrian territory for the rebel Free Syrian Army. The FSA has claimed increased successes and appears intent on taking its fight to Syria's urban areas.
Rami Abdel Rahman, head of the UK-based Syrian Observatory for Human Rights, told the AFP news agency that yesterday saw regime forces use artillery close to the capital for the first time and "violent clashes are taking place around positions of the Republican Guard in Qudssaya and al-Hama" – about five miles from Damascus.
Shahin, a Syrian activist in al-Hama, told The Independent that the FSA was battling Republican Guard Forces, the Syrian Army, and "buses of Shabiha" who had been sent into the area. Shelling began around 3.30am and lasted several hours. "We have never seen anything like this," he said. His network of activists counted at least 17 people killed in al-Hama. He claimed that the Shabiha were carrying dead bodies out of the area so they could not be counted.
Shahin said the shelling of the suburbs was so intense that the FSA was vastly outgunned.