Syria's air force has bombed a rebel-held region near the border with Turkey for a second day, killing at least one person and wounding three others, an official said.
The aerial attack raised the two-day death toll in the region to an estimated 31 people. Nearly 10,000 Syrians have fled into Turkey since Friday, seeking safety from shelling and bombing.
An Associated Press journalist saw air strikes around the Syrian town of Ras al-Ayn, just across the border from the southeastern Turkish town of Ceylanpinar. Plumes of smoke rose into the sky and Turkish ambulances rushed to the border to ferry wounded Syrians to Turkish hospitals.
An official from the Ceylanpinar mayor's office reported four airstrikes. It was not clear whether one or several planes were involved. He spoke on condition of anonymity because he was not authorised to speak to reporters.
The official said one of the four wounded Syrians brought into Turkey for medical treatment had died. He said an estimated 20 people died during Monday's air-raid in Ras al-Ayn and 10 others from the town died Monday in Turkey of their wounds.
The violence in Syria has killed more than 36,000 people since an uprising against President Bashar Assad's regime began in March 2011. Hundreds of thousands have fled into neighbouring Turkey, Jordan, Lebanon and Iraq.
Syrian rebels wrested control of Ras al-Ayn from the Assad regime forces last week. The town is in the predominantly Kurdish oil-producing northeastern province of al-Hasaka.
The fighting in Ras al-Ayn touched off a massive flow of refugees on Friday, and more refugees fled into Ceylanpinar on Monday and Tuesday.
In Paris, French Defense Minister Jean-Yves Le Drian called the creation of the new Syrian opposition group in the Qatari capital of Doha "a significant step forward"— but said the group didn't yet merit international recognition as Syria's provisional government.
"It's not yet a sufficient step forward for it to constitute a provisional government that can be recognized at the international level, but it's on the right track. I would also say in military terms . so it's necessary to translate the Doha accord into military terms."
The deal was reached Sunday after more than a week of meetings, a move some hope could boost efforts to secure international support to oust Assad's regime.
Turkish Foreign Minister Ahmet Davutoglu, speaking to journalists in Rome late Monday, said Turkey had formally protested the bombings close to its border to the Syrian government, saying the attacks were endangering Turkey's security. He said Turkey had also reported the incident to NATO allies and to the UN Security Council.
The Syrian jet did not infringe Turkey's border, he said, adding that Turkey would have responded if it had.
The UN refugee agency said the insecurity has forced it to withdraw five of its 12 staff from Syria's al-Hasaka province, where Ras al-Ayn is located, and led to aid losses in Damascus and Aleppo.
A Syrian Arab Red Crescent warehouse in Aleppo was apparently shelled and 13,000 blankets burned, UN refugee spokeswoman Melissa Fleming said Tuesday in Geneva.
She said "recent deliveries have been very difficult," particularly in Damascus, where aid operations were disrupted for two days and a truck carrying 600 blankets was hijacked outside the city.