BEIRUT: The Syrian army pressed its offensive against rebels, bombarding the city of Douma near Damascus, and Turkey said it had scrambled warplanes after Syrian helicopters flew near its border.
Turkey's armed forces command said the fighters took off on Monday when Syrian transport helicopters were spotted flying near the frontier, without entering Turkish air space. It was the third day in a row that Turkey had scrambled its F-16s.
Syrian President Bashar al-Assad told a Turkish daily he wished his forces had not shot down a Turkish jet last month and that he would not allow tensions with Turkey to lead to war.
"We learned it belonged to Turkey after shooting it down. I say 100 percent 'if only we had not shot it down'," Turkey's Cumhuriyet daily quoted Assad as saying.
A Syrian general and 84 soldiers were the latest to defect and flee to Turkey on Monday. But army and government defections have so far failed to shake Assad's 12-year grip on power.
Assad told Cumhuriyet he was not bent on staying in office come what may but gave no hint he was ready to quit.
"If my staying or going saved my people and country, why would I hold on? I wouldn't even stay one day," he said.
"If the opposite is true, that is, if the people don't want me, then there are in any case elections. If the people wanted, they would send me away," Assad was quoted as saying.
The Syrian leader responded with force when peaceful protests erupted against him in March last year and has turned his troops and tanks on demonstrators and insurgents alike.
More violence erupted on Tuesday with the Syrian Observatory for Human Rights, a group which compiles reports from rebels, saying 56 people were killed across the country, including 34 civilians.
Opposition leaders say more than 15,000 people have been killed since the uprising began in March 2011.
Neither Assad nor his enemies have shown much interest in compromise as Syria slides deeper into a civil war, fuelling animosity between majority Sunni Muslims and the president's minority Alawites who control the military and security forces.
"There was heavy shelling all morning," said Abu Rami, an activist in Homs, a main target of an army onslaught on rebel strongholds. "We are living with little food and little water."
The army on Tuesday shelled places near Douma to which the embattled city's residents had fled at the weekend, Omar Hamzeh, another activist, said, adding that at least six people had been killed.
Refugee activists along the Turkish-Syrian border said two people had also been killed when the army carried out artillery raids on the town of Saqlin, around six km (3.7 miles) from Turkey.
A police officer who defected from the northern city of Aleppo and crossed into Turkey on Tuesday said the army had been firing artillery rounds from areas around the city to rebellious areas to the north and east.
"I left Aleppo and the sound of artillery fire was shaking the ground in Hamdaniya," the officer said, referring to his eastern Aleppo suburb. He declined to be named.
Turkey's southern Hatay province along the Syrian border has become a safe haven for rebel fighters and defectors from the Syrian army. There are also more than 35,000 Syrian refugees now taking shelter in camps in southern Turkey.
Diplomacy has so far failed to curb the bloodshed. World powers agreed at the weekend to support talks on a transitional government. But they failed to narrow differences between the West and Russia over Western demands that Assad must go.
Turkey, which has long demanded the Syrian leader's removal, said Assad's role was over, but advised the Syrian opposition to accept envoy Kofi Annan's internationally endorsed proposal.
"Our task is not to pressure the opposition or to persuade them of something," Turkish Foreign Minister Ahmet Davutoglu told Sky News Arabia in Cairo, where opposition groups were meeting for a second day.
He said Annan's mediation role meant the opposition would not have to negotiate with Assad under the transition plan.
"Thus I believe that accepting the Geneva statement would be a positive thing from the opposition," he said.
His Russian counterpart Sergei Lavrov said Syrian opposition leaders would hold talks in Moscow next week. But it was not clear if they would include any from the mainstream Syrian National Council (SNC), backed by the West and Turkey.
"We will use this coming meeting with yet another Syrian opposition group to continue work to end violence and start Syrian dialogue between the government and all groups of the Syrian opposition as soon as possible," Lavrov said.
Russia says the Geneva agreement does not imply that Assad must be excluded from power. Western powers insist that it does.
Moscow is deeply suspicious of anti-Assad insurgents, echoing Damascus's line that they are all Islamist militants.
Washington too, has reservations about the wisdom of backing an armed opposition it regards as ill-organised and disparate, with some connections to al Qaeda-linked militants.
The rebel Free Syrian Army, an umbrella group of armed factions, boycotted the SNC gathering in Cairo, where the Arab League was urging Islamist and secular groups to end their quarrels and form a credible alternative authority to Assad.
Some Syrian dissidents argue that armed Islamist militants are indeed likely to come to the fore if the outside world leaves the country to the mercy of Assad's forces.
Iran, an ally of Assad, which, along with its regional rival Saudi Arabia, Assad's adversary, was excluded from the Geneva conference, said Damascus wanted reform but not foreign interference or "terrorist activities".
"Syria ... has been the main axis of resistance (against Israel). Therefore it is natural that Western governments and the American government try to take their revenge," said Saeed Jalili, head of Iran's Supreme National Security Council.
Syria's chief of staff, General Fahd Jassem al-Freij, said the nation was at war with conspirators seeking its destruction.
With diplomatic efforts failing to gain traction, the United States may come under pressure from Gulf Arab hawks, notably Saudi Arabia and Qatar, to do more to help the rebels when the "Friends of Syria" forum gathers in Paris on Friday.
Russia, which has criticised the "Friends" for favouring only one side in Syria's conflict, has turned down an invitation to the meeting, French Foreign Minister Laurent Fabius said.
Syrian opposition leaders reject Russia's insistence on a dialogue with the government, saying Assad's removal has to be the first step because of what he has inflicted on his people.
New York-based Human Rights Watch issued a report on "an archipelago" of Syrian state torture centres, citing accounts of victims who said they were beaten, burned with acid, sexually assaulted or had their fingernails torn out.
In Cairo, some Syrian opposition activists described ruthless attacks by government forces on cities such as Homs.
"The city has been bombarded non-stop for months," said Khaled Abul Salah, an activist from Homs. "Anyone wounded dies as there is no way they can leave town or go to hospital."