The disaster began on Monday when heavy rains hit the West African nation's capital of Freetown and the partial collapse of a hillside triggered mudslides, engulfing homes and wreaking destruction.
The United Nations humanitarian agency put the death toll at 409 on Friday.
Mass burials begun as an estimated 600 people remain missing.
People continue to search through tons of mud and debris amid the remains of mangled buildings.
Rainfall also remains in the forecast for the coming days, slowing recovery efforts.
Sierra Leone buried at least 300 victims of devastating floods on Thursday, as fears grew of more mudslides.
The government has hired 600 gravediggers for burials in a cemetery that holds victims of the 2014-15 Ebola outbreak that killed thousands in the country.
Sierra Leone President Ernest Bai Koroma joined mourners for burials on Thursday.
Many people have been unable to find loved ones as many victims were too mangled and decomposed to be identified, but the government has vowed to hold respectful burials for all.
