Iran said Tuesday that arrests were made in the downing of a Ukrainian passenger jet that killed all 176 people aboard shortly after it left Tehran.

Iran had first denied allegations that a missile brought down the plane, which was headed for Kyiv, but said Saturday that the airliner was downed due to "human error."

Iranian Judiciary spokesman Gholamhossein Esmaili said in a statement that "extensive investigations have taken place and some individuals are arrested," according to The Associated Press. The statement reportedly did not say how many people have been arrested or name them.

Iranian President Hassan Rouhani during a speech televised in Iran also called for a special court with a ranking judge and "dozens of experts," according to the AP.

"This is not an ordinary case. The entire ... world will be watching this court," he said.

"The responsibility falls on more than just one person," he reportedly added, and said that those found culpable "should be punished."

Iran's announcement follows anti-government protests that filled the streets of Tehran on Saturday after the government said it mistakenly shot down the commercial plane.

Rouhani, in his speech Tuesday, reportedly repeated Iran's comments that the mistake was made due to U.S. aggression.

Iranian Foreign Minister Mohammed Javad Zarif said last week that a preliminary internal investigation found that "human error at time of crisis caused by U.S. adventurism led to disaster."

The jet was shot down after Tehran launched missiles at two military bases housing U.S. troops in Iraq in retaliation for a drone strike that killed Iranian Gen. Qassem Soleimani in Baghdad.

Ukraine and Canada have demanded accountability from Iran. Among the victims were 11 Ukrainians and 57 Canadians.