A Syrian government delegation heading to peace talks in Switzerland was held up for hours in Athens after a Greek firm refused to refuel the plane they were travelling in.
Vassilis Alevizopoulos, head of Greece's Civil Aviation Workers Union, said a fuel firm had refused to refuel it because of European Union sanctions against Syria.
Syrian state television issued a terse statement saying the four-hour delay could cause foreign minister Walid al-Moualem to miss his meeting with UN chief Ban Ki-Moon. It said the plane had later resumed its flight.
Greek police have asked for permission to check the phone records of Golden Dawn politicians as part of an investigation into the killing of a anti-racism rapper by a supporter of the far-right party, police said.
The government has already asked judges to investigate links between the party, which won 7% of the vote in the last election, and the death of Pavlos Fissas, who was stabbed to death on Tuesday night, after being ambushed a crowd of 30.
A police officer told Reuters that they want to establish if Golden Dawn politicians or local party chiefs called supporters on the evening of the death.
The government says it believed the party is a criminal organisation and a threat to public safety.
Greek Prime Minister Antonis Samaras has called for calm during an "extremely critical time" for the country after an anti-fascist rapper was fatally stabbed by a man allegedly linked to far-right party Golden Dawn.
Samaras said in a televised address to the nation: "This government is determined to not allow descendents of Nazis to poison society, to commit crimes, to terrorise and to undermine the foundations of a country that gave birth to democracy."
Golden Dawn, Greece's third most popular party, insisted it had nothing to do with the killing and has condemned the attack.
Those who accused the party were "wretched sycophants" trying to win votes, the far-right party added.
Far-right Greek party Golden Dawn, who have been linked to the fatal stabbing of an anti-fascist rapper, could be banned by the government, The Guardian reports.
Nikos Dendias, public order minister, said emergency legislation would be tabled that would seek to outlaw the group, adding that the attack showed "in the clearest way (the party's) intentions."
Prominent ant-fascist Pavlos Fyssas, 34, died after around 30 Golden Dawn supporters attacked him and seven of his friends.
A 45-year-old man has allegedly confessed to the stabbing of Fyssas' - also known as Killah P - and was pictured today being escorted by a policeman as they left the prosecutor's office in Piraeus, near Athens.
Protests and violence erupted after the death of the anti-fascist campaigner with Greece's deputy Prime Minister Evangelos Venizelos saying the group must be treated as a "criminal organisation".