Syrian activists and a Turkish official said Syria's air force bombed a rebel-held region near the border for a second day Tuesday, killing at least one person and wounding three others.
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 on Tuesday. It was not clear whether one or several planes were involved. He spoke on condition of anonymity because he was not authorized to speak to reporters.
The official said one of the four wounded Syrians brought into Turkey for medical treatment Tuesday 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.
Amateur videos posted online by activists showed people frantically fleeing Ras al-Ayn with their belongings. In one video, a child screamed uncontrollably as her father tried to soothe her fear. The videos appeared consistent with AP reporting from the area.
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 neighboring 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.
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 U.N. Security Council.
The Syrian jet did not infringe Turkey's border, he said, adding that Turkey would have responded if it had.
In the Damascus suburb of Ein el-Feiha, an area popular with restaurants and shops, a car bomb exploded at afternoon rush hour, causing a large number casualties, according to activists and state-run news agency SANA said.
The U.N. 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, U.N. 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.
Associated Press writers Mathew Lee in Washington, Mehmet Guzel in Ceylanpinar, Turkey, Suzan Fraser in Ankara, Turkey, Angela Charleton in Paris and John Heilprin in Geneva contributed.