Thousands of people marched through Bucharest on Sunday as the death toll from a disco fire on Friday reached 30.
Police said 10,000 people marched from University Square to the scene of the blaze, where a sea of flowers and candles has been laid by mourners.
Authorities said three more victims had died of their injuries and added that the toll could still rise significantly.
“I came to pay homage to those who died and to show my support for those who are fighting for their lives,” said one marcher, Gabriel Mistodie. “It was a tragedy caused in a way by corruption, indifference and incompetence … and a sign that things should change in Romanian society.”
Romanian media have attacked as “irresponsible” the authorities and the owners of the Colectivu nightclub where the fire and a subsequent stampede killed 27 on the spot and left nearly 200 injured.
About 140 were still in hospital, with 35 in a critical condition, according to state secretary for health Raed Arafat.
President Klaus Iohannis on Saturday pointed to “indications” of safety failings at the nightclub, a former shoe factory.