Police said that one woman identified as Munni and four children were killed and at least seven injured after a three-storey building collapsed in northwest Delhi's Ashok Vihar on Wednesday. Two of the children were brothers, aged around 10 years, and one was a boy and another was his sister aged below five years. The injured have been rushed to Deep Chand Bandhu Hospital. They said that several people were still feared to be trapped under the debris and rescue teams are working at the spot. An officer said that they received a call about the incident at 9.25 am and six fire tenders were rushed to the spot near Sawan Park. Two teams of the NDRF have been mobilised for rescue operations, a NDRF spokesperson said. A senior North Delhi Municipal Corporation official said the building was about 20 years old. Its structure was weak and in a deteriorated condition, the official added. <div class="article-tags hidden-xs hidden-sm"></div>