A plane carrying the Syrian delegation to crucial peace talks in Switzerland finally took off from Athens after being blocked there for hours Tuesday, according to AFP reporters at the airport.
The plane took off from the Greek capital at 5:05 pm (1505 GMT), just over five hours after touching down at the airport.
An official Syrian source said Greek authorities had been refusing to refuel the plane, while a Greek civil aviation spokesman said it was being inspected and that a flight plan had not been submitted.
Syrian state television said the delay could lead to the cancellation of meetings, including one between Syrian Foreign Minister Walid Muallem and UN Secretary General Ban Ki-moon.
The Syrian source said the plane had been blocked "because the Greek authorities refuse to provide it with fuel".
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It was not immediately clear why the plane -- a mid-sized Tupolev, according to AFP reporters -- would have needed to stop in Athens for refuelling.
In Athens, a civil aviation spokesman confirmed to AFP that the plane, which airport authorities described as "a Syrian Air charter", had been blocked.
Foreign ministry spokesman Konstantinos Koutras said it was a "procedural" matter.
"The problem stemmed from the refusal of two private companies to refuel the plane owing to the embargo" against the Syrian regime, another foreign ministry source said.
"Following steps taken by the foreign ministry, the problem was solved," he added.
The so-called Geneva II conference begins on Wednesday in the Swiss lakeside city of Montreux, where representatives from nearly 40 regional and world powers will be seeking a way out of the nearly three-year Syria crisis.
Those meetings will be followed on Friday by direct talks in Geneva between representatives of the opposition and of Syrian President Bashar al-Assad's regime, which, according to a Russian official, could last seven to 10 days.