Rescuers digging for victims under rubble of collapsed building in Tehran
Rescue teams in the Iranian capital are still working to reach firefighters and other victims believed to be under the rubble of a commercial building that collapsed after a huge fire on Thursday.
Iranian officials have yet to offer definitive casualty figures for the disaster in Tehran, but state-run Press TV reported on Thursday that 30 firefighters had been killed.
Tehran mayor Mohammad Bagher Ghalibaf said more than 20 firefighters had been killed and promised further updates.
Mr Ghalibaf also said there were no civilians inside the building at the time of the collapse, though witnesses said people had slipped through a police cordon to try to save their valuables inside the burning building.
On Friday, authorities said an injured firefighter died in a local hospital. No survivors or bodies have been pulled out of the rubble so far.
The disaster had stunned many Iranians and triggered an outpouring of grief across Tehran.
Iran's government announced that Saturday would be a day of mourning for the nation following the incident that "claimed lives of several people and brave firefighters", according to a statement carried by the official IRNA news agency.
Jalal Maleki, spokesman for Tehran Fire Department, told state TV that along with firefighters who are believed to be under the rubble, "we assume that there are some other people".
Iranian media said Behnam Mirzakhani, one of the firefighters in hospital in Tehran, died on Friday from his injuries sustained in the building's collapse.
A total of 84 people had been reported injured, but only five remained in hospital, said Pirhossein Kolivand, head of the country's emergency department.
The disaster at the 17-storey Plasco building, inadvertently shown live on state television reporting from the site after the building was engulfed in fire on Thursday morning, came after authorities said they repeatedly warned tenants about blocking stairwells with fabric from cramped garment workshops on its upper floors.
The high-rise was home to more than 500 garment and clothing shops, offices and warehouses, and was full of chemical materials, authorities said.
The blaze and the subsequent collapse stunned the city and firefighters and others openly wept on the streets, holding each other for support. Dozens of people lined up to donate blood.
Smoke was still seen rising occasionally from the ruins on Friday.
Workers were digging several tunnels from buildings next door to reach the basement of the collapsed building, and teams of rescue dogs were also at the site.
Authorities described the building, built more than five decades ago, as having a weak structure. Thursday's fire was the worst in Tehran since a 2005 blaze at a historic mosque killed 59 worshipers and injured nearly 200 others.