This video shows chaos breaking out in Serbia's parliament on Tuesday.
At least three politicians were injured when smoke bombs and flares were thrown.
Lawmakers were scheduled to vote on a law that would increase funding for university education, but opposition parties insisted the session was illegal and should first confirm the resignation of Prime Minister Milos Vucevic and his government.
The incident reflects a deep political crisis in the Balkan country where months-long anti-corruption protests have rattled a populist government.
Vucevic resigned the post in January as authorities faced sweeling protests over a collapse in November of a concrete canopy in the Serbia's north that killed 15 people.