A Syrian fighter jet crashed in eastern Syria on Monday, state television said, hours after rebels said they had shot down a jet in the same area.
The official news channel Syria TV said the plane crashed due to technical problems during a "regular training mission," while state news agency SANA said the pilot had ejected himsel from the plane and that a search party was underway.
Anti-Assad activists uploaded videos on YouTube, said to be from the town of Mohassen in Syria's eastern province of Deir al-Zor, showing a warplane streaking through the skies amid heavy gunfire then suddenly erupting into flames and beginning to swirl, leaving behind a trail of smoke.
"God is greatest! A MiG fighter jet has been hit in the town of Mohassen," the activist shouted. There was no indication from the video as to whether the jet had been struck by rebel gunfire or an anti-aircraft missile. It was also not possible to verify the location or date of the video.
An opposition source working with rebels in the area said the insurgents used anti-aircraft guns to down the jet. "It was a Mig-21 brought down by a 14.5 anti-aircraft gun, the biggest in the rebel arsenal. The plane was flying too low and was within range. We have no information whether the pilot survived," the source said.
The U.K.-based activist group Syrian Observatory for Human Rights said the plane was hit as it was conducting air raids on the town of Mohassen. The group quoted activists in the area as saying the plane was hit with fire from a heavy machine gun used by rebels in the area.
Observatory Director Rami Abdul-Rahman said he was told by locals that the rebels captured the pilot, a colonel, alive.
In recent months the government has begun to use its air power to try to crush a 17-month-old uprising. The downing of a warplane would be a rare event for lightly armed rebels faced with the superior weaponry of President Bashar Assad's forces.
Assad says he welcomes talks with opposition
Also Monday, Syria's ambassador to Iran was quoted as saying the government would welcome dialogue with opposition groups to end the conflict. But he said talks must be supervised by President Assad - a condition rebels are unlikely to accept.
"The government of Bashar Assad welcomes logical discussions with opposition groups in Syria. The main condition is that these discussions take place under the supervision of the president," Ambassador Hamed Hassan said, according to Iran's state news agency IRNA.
He also repeated Syria's assertion that it was being attacked by "terrorist" groups, and blamed the failure to implement the plan of UN peace envoy Kofi Annan on other countries.
Meanwhile, a Syrian diplomat working at the United Nations in Geneva has joined his country's opposition after deciding he can no longer represent President Assad's regime.
A spokesman for the UN Human Rights Council, Rolando Gomez, identified the Syrian as Danny al-Baaj and described him as a junior member of his country's UN mission.
Syria is not a member of the 47-nation council, but al-Baaj worked with it as part of his duties. The uprising in Syria has been a major concern of the council since starting in March 2011.
A growing number of Syrian officials have switched to the opposition as the months have worn on.
Al-Baaj's family said he decided several days ago he could no longer represent Assad, but had not determined his next move.
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