A 10-story building collapsed in southwestern Iran on Monday, killing at least four people and injuring dozens of others, officials said.
Mojtaba Khaledi, spokesman for Iran's national medical emergency organization, said 25 people were injured in the collapse in the city of Abadan.
Some reports, however, put the death toll at five and the number of injured at 80.
More than 150 people were inside the under-construction Metro Pol commercial building on the busy Amiri Street when it collapsed, Anadolu Agency learned from official sources.
The reason for the collapse was not immediately known. Rescue operations were underway when the latest reports came in. Nearby buildings have all been evacuated.
Mehdi Valipour, the head of Iran's Red Crescent Society, was quoted as saying by local media that at least 80 people could be trapped under the rubble.
The incident was reported at around 12:30 local time (0800GMT).
Provincial officials in Abadan told state media that the building was under construction in a congested residential area, which could push the toll higher.
Videos and photos circulating online showed injured people being rushed to hospitals, some in a critical state, while people queued up in front of hospitals to donate blood.
According to Waheed Shabani, managing director of the Red Crescent Society in the Khuzestan province, four rapid reaction teams from neighboring cities were dispatched to the area to assist with rescue and relief efforts.