“The death toll has risen slightly above 500,” Vice President Victor Bockarie Foh said at a ceremony to receive relief supplies provided by Japan.
Separately, government spokesman Abdulai Bayratay said 810 people were listed as missing, a figure that concurs with estimates by NGOs in the past few days.
The city of Freetown — capital of one of the world’s poorest countries — was struck by devastating floods and a mudslide on the night of August 13-14.
The previous toll, given by the city’s central morgue, stood at 499 dead, 156 of them children.
Vandy Rogers, a senior official with the country’s national emergency services, said the number of people who had been “directly affected” by the disaster was around 6,000.
On Tuesday, the authorities warned tourists and locals against swimming in Freetown’s waters after 60 bodies washed up.
Baratay said soldiers, supported by forensic experts from Spain, would continue to search for those missing, “as most families want bodies of their loved ones (to) be evacuated and given a dignified burial.”
The location of the mudslide would later be turned into a memorial, he said.
The disaster was preceded by torrential rain that saturated the soil and left vulnerable slopes liable to collapse, the interim head of the Sierra Leone Institution of Geoscientists, Solomon Tucker, said.