About 70 people were injured in the fire and 15 homes destroyed,according to the St. John's Ambulance, which has been attending to casualties at the scene. Some of the injured are hospitalized in critical condition, Kenyan President Uhuru Kenyatta said in a statement. The fire broke out at around 2:30 a.m. local time Thursday and was contained two hours later, the ambulance service said. Gikomba is one of the largest markets in Nairobi, selling everything from timber to secondhand clothing. Fire outbreaks reportedly are frequent there.Police said they are still trying to establish the cause of the blaze. Kenyatta paid tribute to the victims as he vowed to ensure such a tragedy does not happen again. "Prayer will be followed by action. We will support victims and their families. … We will fully investigate the cause of the fire. …," he said in his statement."The national Government and Nairobi County will sit together for a full review of our emergency services, and our disaster preparedness. We owe the victims, and the people of Nairobi, a clear, credible plan to end these fires." Kenya's Red Cross said it has set up a desk to help people search for loved ones and is also offering support services.