Of the latest 49 cases, 35 are under quarantine, while there are also 14 of their contacts.
The Covid-19 infections among garment factories in the Katunayake investment promotion zone have now risen to 180 patients.
The Board of Investment says 930 PCR tests were conducted within the zone yesterday.
Elsewhere, two more patients have been reported from Avissawella and Ratmalana and at least 35 of their contact sent for quarantine.
A curfew remains in force in 19 police areas of the Gampaha district with movements made strictly limited, says police spokesman DIG Ajith Rohana.
Police have so far arrested 203 curfew violators and 40 of their vehicles seized.
Meanwhile, the Department of Immigration and Emigration and the Department of Motor Traffic have decided to reopen for limited numbers of the public in the coming week.
The public should obtain an appointment via telephone in advance to visit these Departments to get their needs attended to.