A group of Iranian protesters demanded that the country’s Supreme Leader Ayatollah Ali Khamenei step down on Saturday after the government said its military had by mistake shot down a Ukrainian plane, killing all 176 people on board.

Those aboard the doomed flight included 82 Iranians, 63 Canadians and 11 Ukrainians, including the nine crew members. Ten passengers were from Sweden, four from Afghanistan, three from Germany and three from the United Kingdom.

The protesters in Iran expressed anger at what they perceive as an initial cover-up.

Prior to Iran’s admission Saturday, it had denied shooting down the Ukraine International Airlines flight, which crashed shortly after it took off from Tehran early Wednesday.

But U.S. intelligence officials had said earlier that evidence suggested that the plane was shot down by an Iranian missile by mistake, multiple officials said.

“Commander-in-chief (Khamenei) resign, resign,” videos posted on Twitter showed hundreds of people chanting, in front of Tehran’s Amir Kabir university.

The crowds included middle-class professionals as well as students.