RIO DE JANEIRO, Jan. 25 (Xinhua) -- At least four people were injured when two buildings collapsed in Rio on Wednesday evening after office hours.
The two buildings, one with 17 storeys, the other with 11, were located in Rio's downtown area, a commercial district full of pedestrians.
According to the local Civil Defense, 60 firefighters are now working on the scene, trying to find more victims.
Four subway stations have been closed due to the accident. The area has been closed off, and electricity has been cut off to prevent fires. Technicians are trying to close the underground pipes which supply gas to the buildings.
Rio's Mayor Eduardo Paes and Health Secretary Sergio Cortes are both at the site, and the mayor is expected to make a statement in the next hours.
The cause of the collapses remains unknown.
Neighbors reported that three floors of one of the collapsed buildings were undergoing renovations. Witnesses said there was an explosion, and the larger building came down as if it had imploded.
There may also have been a gas leak, which was the cause of a major explosion which hit another building in downtown Rio last year, killing three people.