The National Resistance Council of Iran (NRCI) said the demonstration against a wave of executions in Iran was cancelled "after business hours" on Thursday by the Paris police, "citing bogus reasons".

The police order said that "in the current particularly tense national and international context there is a serious risk that, during this demonstration, clashes may occur between activists holding opposing views which could seriously disrupt public order".

It noted that the gathering point and route of the planned march was due to pass "close to several public buildings and diplomatic missions".

The organisers, who have filed an emergency motion to reverse the ban, suggested it was linked to a call hours before the last-minute cancellation on Thursday evening between the French and Iranian foreign ministers.

French Foreign Minister Jean-Noel Barrot "did not mention this demonstration or request its cancellation", the ministry said.

The NRCI is the political arm of the People's Mujahedin of Iran (PMOI or its Persian acronym MEK), which is outlawed as a "terrorist" group by the Islamic republic.

The group has organised many protests in Paris previously without incident, including in recent months during nationwide anti-government protests in Iran and the US-Israeli war against the Islamic republic.

It is one of several Iranian diaspora groups, who are often bitterly at loggerheads.

The demonstration -- which organisers expected to draw 100,000 people -- was due to draw awareness to a wave of executions in Iran during the Middle East war.

A deal to end the conflict signed this week between Tehran and Washington was already under strain on Friday.

Rights groups said more than 40 people have been executed in Iran since the war began, many of them people linked to the protests that broke out prior to the war.

At least a dozen men have been hanged recently over links to banned opposition groups including the MEK but also outlawed Kurdish and Sunni Baluch organisations.