Nine more victims of the Romanian nightclub blaze have died of burn-related injuries, bringing the death toll to 41.

Many have blamed lax government safety standards for the deadly blaze at the Colectiv basement nightclub in Bucharest and prime minister Victor Ponta and his cabinet resigned on Wednesday, following mass protests.

Cristian Popescu Piedone, mayor of the district where the nightclub is located, was arrested, along with two town hall staff, for issuing a permit without it being authorised by firefighters, the anti-corruption prosecutors' office said.

He also resigned on Wednesday, saying he was morally guilty for the fire.

Multiple hospitals reported deaths on Saturday from the October 30 blaze, which erupted during a heavy metal concert when a spark from a pyrotechnic show ignited foam decor. Panicked people fled for the sole exit in a stampede, leaving 180 injured.

Adrian Stanculea, spokesman for the state burns hospital, said three men died there, while University Hospital said a man there died.

Raed Arafat, an emergency situations official, said two patients who had been sent to the Netherlands for specialised burns treatment had died, including a 20-year-old Italian woman who was a student in Romania. Eight patients were transported by military plane to the Netherlands for treatment.

Interim prime minister Sorin Campeanu said a patient at the Floreasca emergency hospital in Bucharest also died and a second person died there later.

The ninth person to die on Saturday was a woman who had been in a critical state since the fire. She died at the Bagdasar-Arseni hospital.

Mr Campeanu said 109 other people still remained in hospital, 48 of them in a serious or critical condition.

Late on Saturday, about 2,000 protesters gathered in Bucharest for the fifth consecutive evening, waving Romanian flags and calling for better governance and an end to corruption.

"The political class is inefficient and corrupt. We need a government of technocrats or experts," said Cristina Lotrea, a 22-year-old sociology researcher.

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