Norway summoned the Iranian ambassador in Oslo on November 1 to protest a suspected assassination plot against an Iranian Arab opposition figure in Denmark that allegedly involved a Norwegian citizen of Iranian origin.
Denmark said on October 30 that it suspects the Iranian intelligence service tried to carry out an assassination on its soil. It is now calling for new European Union-wide sanctions against Tehran.
A Norwegian citizen of Iranian background was arrested in Sweden on October 21 in connection with the plot and extradited to Denmark, Swedish police have said.
"We see the situation that has arisen in Denmark as very serious and that a Norwegian citizen of Iranian background is suspected in this case," Norwegian Foreign Minister Ine Eriksen Soereide said.
She said that during her meeting with Iranian Ambassador Mohammad Hassan Habibollah Zadeh, "we underlined that the activity that has come to light through the investigation in Denmark is unacceptable."
The target of the alleged plot was the leader of the Danish branch of the Arab Struggle Movement for the Liberation of Ahvaz (ASMLA), Danish authorities said.
Danish police said they temporarily closed bridges and halted ferry services to neighboring Germany and Sweden at the end of September as part of their attempts to foil the plot.
ASMLA seeks a separate state for ethnic Arabs in Iran's oil-producing southwestern province of Khuzestan. Arabs are a minority in Iran, and some see themselves as under Persian occupation and want independence or autonomy.
The Norwegian citizen has denied the charges, and the Iranian government has also denied the alleged plot.
Danish Prime Minister Lars Lokke Rasmussen on October 31 met with other Nordic prime ministers in Norway and said he hoped to secure broader support for a unified response to Iran.