The Dutch government has recalled its ambassador to Iran in response to the expulsion of two members of staff from its embassy in Tehran.

Foreign affairs minister Stef Blok said the move on Sunday evening was ‘not acceptable and negative for the development of bilateral relations’. Iran had declared the two members of staff persona non grata on February 20.

The incident is the latest escalation in a row that began when the Dutch intelligence service AIVD implicated Tehran in the murder of two opposition activists in Almere in 2015 and The Hague in 2017.

Blok made the findings public on January 8 as the European Union toughened up its sanctions against Iran in retaliation for two ‘thwarted assassinations’ in Paris and Denmark as well as the killings in the Netherlands.

In a written statement to parliament, Blok said his officials had explicitly warned the Iranian ambassador last month not to expel the Dutch embassy staff. ‘The two Dutch diplomats were removed to the Netherlands on Sunday, March 3,’ he wrote. ‘The cabinet has therefore recalled the Dutch ambassador to Tehran for consultation.’

Two Iranian embassy staff members in The Hague were expelled last year when the AIVD first told the minister in private that it believed the government was responsible for the killings of Mohammad Samadi and Ahmad Nissi.

Samadi was killed in 2015 in Almere, where he was working as an electrician under an assumed name. He is suspected of being responsible for a bomb attack on the headquarters of the Islamic Republican Party in Tehran in 1981 in which 73 people died.

Nissi was shot dead in a suburb of The Hague in 2017. His group ASMLA is campaigning for the independence of the southwestern province of Ahwaz (Khuzistan) and has been classed as a terrorist organisation by the Iranian government.

Criminal investigations are under way into both killings.