The EU is no longer qualified to take part in talks on Iran's nuclear programme, a top Iranian official says.
Maj Gen Hassan Firouzabadi, Iran's top military officer, accused the EU of interfering in riots which followed the disputed Iranian elections last month.
Until the EU apologised for this "huge mistake", he said, it had no right to take part in the negotiations.
The EU has yet to comment, but earlier urged Iran to avoid conflict with the international community.
The Iranian presidential elections, held on 12 June, returned President Mahmoud Ahmadinejad to power for a second term in office. But the opposition disputed the result, saying the vote had been rigged.
At least 17 people were killed as supporters of the opposition candidates took to the streets in protest.
Maj Gen Firouzabadi accused some EU members of supporting the riots, and demonstrating their hostility to the Iranian people.
Previously, Iran had aimed its allegations at Britain in particular and at the weekend detained nine local employees at the British embassy. Most have since been released.
The semi-official Iranian Fars news agency accused one of the employees of having "a remarkable role during the recent unrest in managing it behind the scenes".
Mahmoud Ahmadinejad has cancelled a trip to Libya
Britain has dismissed all the allegations as baseless.
Iran says it is enriching uranium for power plants, but some Western countries suspect it plans to build nuclear weapons.
Three EU countries - Britain, France and Germany - have led negotiations over Iran's nuclear programme, along with the United States, Russia and China.
At their last talks, they offered Iran a package of incentives if it would stop its nuclear activities.
But Iran insists that its right to enrich uranium is non-negotiable.
In a separate development, officials in Tehran said the Iranian President Mahmoud Ahmadinejad had cancelled his trip to an African Union summit in Libya.
Mr Ahmadinejad's office did not give any reason for the decision.
His visit would have been one of his first major public appearances abroad since his re-election.