The death toll from a building collapse in Kenya's capital Nairobi has risen to five after rescuers recovered three more bodies from the debris on Thursday, two weeks after the disaster.

Police said recovery operations were nearing completion, while 16 people were still believed to be missing since the 18-storey building collapsed on October 23.

Four people were rescued alive from the building, which came down along a busy commercial street while its upper floors were under construction. Its ground and basement floors had been rented out to businesses, including an electronics shop, grocery store, textile shop and butchery.

Nairobi County Governor Johnson Sakaja said the building had not received construction approval and that renting out its completed floors was also illegal.

He blamed weak enforcement of construction regulations and inadequate penalties for developers' disregard for building laws.

Investigators have questioned the developer, but no arrests have been made. The building was owned by two partners under a joint venture agreement.

Government data show that Kenya recorded 98 building collapses over the past five years, leaving 104 people dead and 80 injured.

Kenya is co-hosting an International Conference on Strengthening Search and Rescue Services in Africa with the United Nations and the Russian government. Participants are discussing technologies and innovations to improve rescue operations and emergency response capacity across the continent.

Three days after the Nairobi collapse, the government partnered with a Chinese company that deployed thermal imaging technology at the site. The technology detected two people trapped beneath the rubble.