Tens of thousands of protesters led by university students have held a noisy rally outside Serbia's state television headquarters in Belgrade to protest what they called the broadcaster's pro-government bias.

The demonstration is one of the biggest in years against alleged pro-government bias by the RTS television station.

Tens of thousands of anti-government protesters in Belgrade on Sunday switched on the lights on their mobile phones and stood in silence for 15 minutes to commemorate victims of a railway station roof collapse for which they blame authorities.