Kenya National Disaster Operation Centre director Colonel Nathan Kigotho said 135 people have so far been rescued from the six-story building, which collapsed due to heavy rains which pounded Nairobi on Friday evening.
"Rescuers retrieved two more bodies from the rubble on Monday bringing the death toll so far to 22. We have also rescued 135 people from the rubble and operation still continues," Kigotho told Xinhua by telephone.
Kenya Red Cross Society said more than 70 people were still unaccounted for amid reports more people were still trapped under the wreckage of the building.
The agency said rescuers were racing against time to save the lives of people still trapped in the rubble. Those who had slight injuries were treated and discharged while some who suffered fractures in the arms and legs were still being treated at hospitals.
The owner of the building has been arrested and is due in court on Tuesday to face charges of manslaughter, according to the police.
The rescue team led by the military has since started using heavy machinery to lift up debris from the site as hope of finding any more people alive diminishes.
Health Cabinet Secretary Dr. Cleopa Mailu said on Monday that the ministry is working in collaboration with the Kenyatta National Hospital (KNH) to ensure that all survivors receive ample treatment and medical care.
Mailu, who visited survivors at the Kenyatta National Hospital, said the survivors were positively responding to treatment and their status was now in good condition.
He further pointed out that the 12 survivors under medication will also be subjected to psychological and social support before being discharged.
The rescuers said two floors sank into the ground and people are still feared trapped inside the building which collapsed following heavy rains that have been pounding Nairobi and its environs.
The Red Cross said it has mobilized partner support to provide heavy machinery resources, and participating in search and rescue.
Currently, the humanitarian agency is working with National Youth Service (NYS), and the military, which have deployed machinery to support the operation.
The building, according to residents, was built on a waterway, blocking the passage of water which could have weakened its structure.
There has been a heavy downpour in Nairobi for the last two days, with rain intensity rising Friday evening.
Many roads and suburbs in the capital were flooded due to the heavy rains leading to traffic jams that left many commuters stranded in the city centre.
Families have also been displaced, with KRCS confirming that approximately 150 households had been affected and were currently camping at a local government office.
The weatherman has said that the rains would continue in the coming weeks.