The military is involved in the search operations at the site.
President Maithripala Sirisenahas has instructed officials to provide maximum relief to the people who were affected due to the disaster.
Several houses were buried after the Meethotamulla garbage mountain collapsed on Friday.
A fire had also broken out at the site and the Air Force was deployed to douse the flames.
The residents of the area have been protesting over the past several months urging the authorities to move the garbage to another location.