Norway summoned the Iranian ambassador Thursday over a suspected assassination plot against an Iranian Arab opposition figure in Denmark involving a Norwegian citizen of Iranian background. 

Denmark said Tuesday that it suspected the Iranian government intelligence service had tried to carry out an assassination on its soil. It is now calling for fresh European Union sanctions against the Islamic Republic. 

A Norwegian citizen of Iranian background was arrested in Sweden Oct. 21 in connection with the plot and extradited to Denmark, Swedish security police have said. 

“During the meeting we underlined that the activity that has come to light through the investigation in Denmark is unacceptable,” Foreign Minister Ine Eriksen Soereide said in a statement. 

“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,” she added. 

The attack was meant to target the leader of the Danish branch of the Arab Struggle Movement for the Liberation of Ahvaz (ASMLA), Danish intelligence chief Finn Borch Andersen said. Tehran has blamed ASMLA)for a terror attack on a military parade in Ahvaz on Sept. 22 that left at least 25 people dead.

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 any connection with what Norway suspects is a plot.