Crowds forced their way into the ruins of a 10-storey building in Abadan that crumbled in one of Iran's deadliest such disasters in years.

So far 13 people have been arrested for building violations, authorities say.
So far 13 people have been arrested for building violations, authorities say. (AFP)

Iranian police have used tear gas and fired shots in the air to disperse another night of protests over a deadly building collapse in the southwestern city of Abadan.

Local media said that a protest in Abadan on Friday night turned violent when crowds forced their way into the ruins of the building, where rescue operations were continuing. 

Police fired tear gas and warning shots, it said.

Footage on social media showed people running for cover. Screams of "Don't shoot, don't shoot" and the sound of gunfire could be heard. 

Unverified video from Khuzestan's port city of Mahshahr also showed protesters shouting: "They stole oil and gas, took our blood".

Reuters could not independently authenticate the footage.

Marches in solidarity with the Abadan protests have also been held in several nearby areas in Khuzestan as well as Shahin Shahr in central Iran and the southern city of Shiraz, according to other unverified postings on social media.

Officials in the oil-producing region of Khuzestan, where Abadan is located, said the death toll had risen to 28 people, and another 37 were injured in Monday's collapse of the 10-storey residential and commercial building. 

READ MORE: Death toll rises in Iran building collapse, rescue efforts underway

Investigating the disaster

Officials are blaming corruption and lax safety standards the collapse of the building, Fars news agency and reports on social media said.

First Vice President Mohammad Mokhber told state television on Friday he believed that "widespread corruption" between the builder, contractor and supervising bodies was responsible for the disaster.

Authorities investigating the disaster have detained Abadan's current and past mayors and several other municipal employees, amid accusations that safety warnings were ignored.

As during earlier protests over food price rises, residents have reported disrupted internet services, an apparent attempt to stop the use of social media to organise rallies and disseminate videos. 

Officials deny blocking internet access.

Source: TRTWorld and agencies