Iran's Ministry of Foreign Affairs is summoning Sweden’s ambassador to condemn the trial of a former Iranian official accused of being involved in thousands of extrajudicial executions during the 1980s. Hamid Noury, 61, has been on trial in Stockholm since last August. Arrested in 2019, he stands accused of being involved in a wave of mass killings in 1988, at the end of the bloody Iran-Iraq war. Rights groups say as many as 30,000 people were killed, although estimates of the final death toll vary significantly. Many of those killed were hung from cranes, a common method of execution by the regime in Tehran. Victims included members of the Mujahideen e-Khalq, a resistance group that sided with Iraqi dictator Saddam Hussein during the war, as well as other opposition groups. Many were allegedly killed after being detained on unexplained charges and being tortured during interrogation. Swedish ambassador Mattias Lentz was summoned following a trial session on Thursday when prosecutors requested the maximum penalty of life imprisonment for Mr Noury. Sweden's foreign ministry in a Twitter post advised its citizens against non-essential travel to Iran “due to the security situation”. Tehran has been accused of taking foreign citizens prisoner on baseless charges to use them as leverage in foreign policy negotiations. Mr Noury is being charged under the principle of universal jurisdiction, which allows Swedish courts to handle serious cases such as war crimes regardless of where the offences were committed.