Syrian President Bashar al-Assad

AFP

Syrian President Bashar al-Assad regretted that his country's defence forces shot down a Turkish fighter jet on June 22, he said in an interview with the Turkish newspaper Cumhuriyet published Tuesday.

"The plane was flying in an air corridor used three times in the past by the Israeli airforce," he said, but added that he regretted the incident -- which has further fuelled tensions between the two former allies -- "100 percent".

Assad rejected Turkey's accusations that the Syrian defence forces intentionally shot down the Turkish F-4 jet, which was on a training mission over the Mediterranean, reports AFP.

"A country at war always acts like this, this plane was flying at a very low altitude and was shot down by anti-aircraft defences which mistook it for an Israeli plane, which attacked Syria in 2007."

He said the soldier who shot down the plane had no radar and could not know to which country the plane belonged.

Assad sent his condolences to the families of the two pilots of the downed plane, who have not been found.

"If this plane had been shot down in international airspace (as maintained by Ankara) we would not have hesitated to apologise," he said.

On Monday, exiled opposition groups tried to forge a common vision for a transition in Syria as they met in Cairo as the UN rights chief accused both the regime and opposition of "serious" violations.

UN High Commissioner for Human Rights Navi Pillay also charged that weapons supplied to the government and opposition were escalating the conflict, warning that "further militarisation" must be avoided.

She spoke as at least 30 people were reportedly killed in new bloodshed across Syria.

Members of Syria's opposition met behind closed doors in Cairo to chart a common vision after criticising a blueprint for transition agreed by the major powers at the weekend.

Arab League chief Nabil al-Arabi, who chaired the two-day meeting attended by around 250 opposition figures, urged the factions "not to waste this opportunity" and to "unite."

Arabi also stressed the need for "a pluralist democratic system that does not discriminate between Syrians."

Nasser al-Qudwa, deputy to UN-Arab League peace envoy Kofi Annan, echoed Arabi's call, telling the opposition to "unify your vision and your performance."

"This is not a choice, but a necessity if the opposition wants to gain the trust of its people in Syria," Qudwa told the meeting which was also attended by the foreign ministers of Turkey, Iraq and Kuwait.

Rebel fighters and activists based in Syria said they were boycotting the meeting, denouncing it as a "conspiracy" and criticising the agenda which they said rejects calls for military intervention.

The statement, signed by the rebel Free Syrian Army and "independent" activists, said the meeting served the interests of the Damascus regime's allies Russia and Iran.

It also slammed the meeting for "ignoring the question of buffer zones protected by the international community, humanitarian corridors, an air embargo and the arming of rebel fighters."

In New York, UN rights chief Pillay briefed the UN Security Council before telling reporters that the violence was being fuelled by arms supplies to both the government and opposition.

"Any further militarisation of the conflict must be avoided at all costs," she said.

While Pillay did not name countries, Russia and Iran are key suppliers to al-Assad's government, and Gulf states, notably Qatar and Saudi Arabia, have given weapons to the increasingly well-armed opposition.