Egyptian rescue teams are working to free 11 people trapped in a high-rise building which collapsed in flames, killing four and injuring more than 40. Cairo security director Nabil el-Azzaby said those killed were two soldiers and two civilians. Most of those still buried in the wreckage had been helping to evacuate the building, he said. The building, in the residential and commercial area of Nasr City, collapsed after a blaze broke out in a storeroom. Fire officers said the building buckled one-and-a-half hours after a blaze broke out on the lower floors, where a shopping centre is based. Sources said the fire started possibly in a fast food restaurant or a home appliances shop next door. Most of the hundreds of tenants in the upper levels were evacuated. **Search *** The BBC's Heba Saleh in Cairo said rescuers were working by floodlight to try and free them from the rubble. Two nearby buildings were also said to have been damaged in the collapse, and their tenants had been evacuated. Housing Minister Mohammad Ibrahim Suleiman was quoted by Mena as saying it was too early to say what had caused the collapse. Nasr City, near the airport, is home to many modern high-rise residential buildings and shopping areas. Cairo's governor said the collapsed building was given planning permission for just four floors. At least seven others were added illegally, said our correspondent. A demolition order was issued for the block 12 years ago, although it was not clear why it was not carried out. Building collapses in Egypt are not uncommon, with buildings regulations sometimes ignored and unauthorised floors added, making existing structures unsafe. At least seven people were killed when a six-storey building collapsed in Cairo last May. **PHOTO CAPTION*** A view of a building which collapsed in Cairo, January 27, 2004 with rescue operation going on. Thirty-three people were injured when a building of more than 10 stories collapsed, trapping another 16 people in the rubble, officials said. Photo by Aladin Abdel Naby/Reuters