Haiti's Interior Ministry says the confirmed death toll in that southwestern zone of the hardest-hit area of the country is now 283.
Officials expect the toll to rise as authorities reach remote places that were left isolated by the storm.
The overall death toll in Haiti is not clear. The headquarters for Haiti's Civil Protection Agency had put the number of confirmed deaths for the whole country at 122.
Bodies have started to appear as waters recede in some areas two days after Matthew smashed concrete walls, flattened palm trees and tore roofs off homes.