Iran has stopped providing fuel for European aircraft because of international sanctions against the Islamic Republic; some Western countries refuse to supply fuel for Iranian planes.
Their flights to Europe have been going via Prague and Bucharest, which have Russian suppliers; Russia does not support the sanctions.
The measures against the Ahmedinejad government are over Iran’s uranium enrichment programme, which the West says is part of a plan to build a nuclear bomb, although Tehran denies the charge.
The European Union has followed the United States, deciding to deny visas to and freeze the assets of 32 Iranian officials who are suspected of acts violating human rights in Iran, notably suppressing voices in the opposition. Brussels has also condemned a recent increase in executions.