Iran’s top Guards commander briefed parliament on Sunday, a day after the armed forces said a Ukrainian airliner was shot down in error in an admission that sparked an angry demonstration. On the day after the rally at Tehran’s Amir Kabir University, tensions appeared to be mounting again on the streets of the capital, with a heavy police presence notably around the iconic Azadi Square south of the centre. Riot police armed with water cannon and batons were seen at Amir Kabir, Sharif and Tehran universities as well as Enqelab Square.