AFP- Rescue teams recovered the bodies of two Iranian firefighters early on Saturday, two days after they were killed while tackling a blaze in Tehran's oldest high-rise.


They were among around 20 firefighters feared to have been killed when the 15-storey Plasco building collapsed on Thursday after a four-hour blaze while emergency services were still evacuating the tower.


One firefighter already died in hospital from his injuries.


Smouldering fires and smoke have complicated the recovery effort as sniffer dogs have combed the rubble.


Tehran's chief pathologist said the degree of the burns had made identification of the dead difficult.


"Even the identity badges they wore on their uniforms were burnt beyond recognition," Massoud Ghadipacha told Iran's ISNA news agency.


The government announced a day of mourning for the firefighters on Saturday, with the cabinet releasing a statement "praising these great men of sacrifice".


President Hassan Rouhani, who visited the site on Saturday, called for an immediate investigation.


Impromptu displays of solidarity and sadness appeared across Iran, with people leaving flowers and lighting candles outside fire stations.


The Plasco building was Iran's oldest high-rise and contained a shopping centre and hundreds of clothing suppliers.


When completed in 1962, it was Iran's tallest building, before being dwarfed by the construction boom of later years.


It was built by Habibollah Elghanian, a prominent Iranian-Jewish businessman who was arrested for alleged ties to Israel and executed after the 1979 Islamic revolution.