Syrian rebels say they've captured the pilot of a government warplane they claimed to have shot down in eastern Syria.
The rebels issued a video that reportedly shows a man identified as pilot Mufid Mohammed Suleiman, surrounded by three armed men.
The man reportedly says he has been treated well and urges Syrian government forces to defect from President Bashar al-Assad's regime.
The authenticity of the video shown on the pan-Arab network Al-Arabiyah could not be independently confirmed.
The release of the video comes amid conflicting accounts over the government fighter jet, which crashed on August 13 in the eastern province of Deir el-Zour.
Syrian state media said the plane crashed due to technical problems during a "regular training mission." The reports said the pilot had ejected from the plane and that a search was under way.
Earlier, Syrian activists released a video that they claimed shows a government Soviet-made MiG warplane catching fire and crashing after being hit by ground fire.
If the claims of the rebels are proven correct, the incident could indicate an escalation of the conflict.
The incident comes as a Syrian diplomat working at the United Nations in Geneva confirmed on August 13 that he had defected.
Danny al-Baaj, one of the first Syrian diplomats in Europe to abandon President Bashar al-Assad's regime, said he no longer felt positioned to do anything for the Syrian people.
Baaj, who announced his resignation on August 10, said he had been planning his defection for some time, and that he had been in contact with a Syrian opposition group based in Paris.
Toll On Civilians Increasing
Meanwhile, the United Nations' chief humanitarian official announced that she will visit Syria and Lebanon between August 14 and 16 because of growing concern over the "deteriorating humanitarian situation" around the Syrian conflict.
Valerie Amos, head of the UN's Office for the Coordination of Humanitarian Affairs, will investigate the effects of the long-running Syrian conflict on civilians remaining in Syria and on those who have fled to neighboring countries such as Lebanon.
According to the UN, some 2 million civilians have been affected by the crisis and more than 1 million are internally displaced. About 140,000 Syrians have fled to Lebanon, Jordan, Turkey, and Iraq.
Amos's impending visit comes as UN monitoring mission chief Babacar Gaye, speaking on August 13 at a news conference in Damascus, said it was clear that the Syrian conflict was escalating.
"It is clear that violence is increasing in many parts of Syria," he said. "The indiscriminate use of heavy weapons by the government and targeted attacks by the opposition in urban centers are inflicting the heavy toll on innocent civilians."
Also on August 13, Iranian President Mahmud Ahmadinejad arrived in Saudi Arabia ahead of a summit on the Syrian conflict, on which Tehran and Riyadh have taken opposing sides.
The summit of the Organization of Islamic Cooperation, a 57-member pan-Muslim body, is to take place on August 14-15 in the holy city of Mecca.
Saudi Arabia has supported Sunni rebels in their fight to overthrow Assad's Shi'ite-dominated regime. Iran, a Shi'ite-majority country, is Assad's biggest ally and has pledged him full support, although it denies providing him with soldiers or arms.
Tehran accuses Saudi Arabia of helping to arm and finance the Syrian rebels.
With reporting by Reuters, AP, and AFP