BRUSSELS (Reuters) -- European Union countries have summoned Iranian ambassadors to protest against the detention of Iranian staff of the British Embassy in Tehran and warned of tougher steps next week if they are not freed.
EU foreign ministers last week urged Iran to release swiftly the Iranian employees of Britain's Tehran embassy and a Greek journalist detained as alleged instigators of street protests over disputed presidential election results.
They warned of a "strong and collective response" against intimidation of diplomatic staff.
At a meeting in Brussels on July 3, the 27 EU states agreed to take a gradual approach towards Tehran that could in future include visa bans and withdrawal of EU ambassadors from Iran, depending on how the situation evolved, an EU official said.
"It is clear we need to show solidarity, that we are unified," Swedish Prime Minister Fredrik Reinfeldt, whose country holds the EU Presidency, told a news conference with French President Nicolas Sarkozy.
Sarkozy said EU states would do all they could to back Britain. "France has always wanted to strengthen the sanctions so that the Iranian leaders really understand that the path they have chosen will be a dead end," he said. "Now it is up to the British to tell us what they need." 'No Option Off The Table'
An EU official said further steps would be considered after the meeting of the Group of Eight major industrialized powers in Italy next week.
Swedish Foreign Minister Carl Bildt said the fact that seven of nine staff originally detained had been freed showed the EU approach was working.
"The EU...agreed to review the situation next week if the staff were not released," he said in a statement. "No option was taken off the table."
Powerful Iranian cleric Ayatollah Ahmad Jannati suggested the detained staff would be put on trial
in the Islamic republic for their alleged role in the post-election unrest.
Britain said it was "very concerned" about the statement.
Bildt's spokeswoman said it would not be acceptable for Iran to charge those still detained or those who had been freed.
The G8 on June 26 deplored the violence stemming from Iran's police sweep against protesters following the disputed election but kept the door open for Iran to enter into talks on its secretive nuclear program.
Mass protests over alleged vote rigging in the June 12 election won by incumbent President Mahmud Ahmadinejad prompted crackdowns by police and Islamic militia. Iranian authorities say the vote was fair.
Last month EU leaders condemned Iran's handling of the protests and called for an investigation into the election.