At least 15 people were missing in a seven-storied building in eastern Kenya's Nairobi capital.

The building collapse occurred on the outskirts of Nairobi on Monday night. The country's rescuers told the information on Tuesday.Kenya Radio Correspondent said the rescue workers have already reached the collapsed building in the War Pipeline Mbakasi area. Local daily The Star said that dozens of people had been evacuated before the building collapsed.Rescue mission coordinator Pius Masai said hundreds of people were there before the building collapsed. However, some people were stuck there while building collapses. The National Disaster Management Unit said that before the accident, everyone was ordered to release the building. 121 people were safely evacuated.Local media said that some people again entered the building after taking them out. Many of them could not leave. There is no idea about the exact number of people trapped inside the building, police said.