Iran announced on Tuesday (Jan 14) its first arrests over the accidental shooting down of a Ukrainian passenger jet, as protesters vented their anger over the catastrophic blunder for a fourth consecutive day.
Nearly two weeks after the US killed a top Iranian commander in Iraq, tensions with the West increased further as EU countries on Tuesday launched an arbitration process charging Tehran with failing to observe commitments in the 2015 nuclear deal, prompting Iran to warn of unspecified "consequences".
The Ukraine International Airlines plane was brought down by a missile shortly after takeoff on Wednesday, killing all 176 passengers and crew on board.
Iran has struggled to contain the fallout over its handling of the air disaster, after initially dismissing Western claims it was brought down by a missile before admitting it on Saturday.
The tragedy has seen hundreds of angry protesters, most of them students, take to the streets, apparently chanting slogans against the Islamic republic.
New videos circulating on social media purported to show fresh protests on Tuesday evening at universities in Tehran, along with clashes between students and Basij militia loyal to the establishment.
It was not possible to immediately verify the videos.
Earlier, AFP correspondents said around 200 mainly masked students gathered at Tehran University on Tuesday and were locked in a tense standoff with youths from the Basij.
"Death to Britain," women clad in black chadours chanted as Basij members burned a cardboard cutout of the British ambassador to Tehran, Rob Macaire, after his brief arrest for allegedly attending a demonstration Saturday.
Kept apart by security forces, the groups eventually parted ways.
AFP journalists said there appeared to be a lower police presence on Tuesday compared to preceding days.
Internet connectivity was significantly lower than usual.