The two others, who tested positive in the past 24 hours, are in Ri-Bhoi district, he said.
While one person is a high risk contact of a COVID-19 patient, another is a returnee from Bihar who tested positive at Umroi town, the official said.
As many as 12 persons from the BSF have so far contracted the virus in Meghalaya.
Health authorities in the state have asked the Border Security Force to get their personnel posted at Lyngkhat village along the Indo-Bangla border tested for COVID-19 after four jawans tested positive since Friday, officials said.
The four BSF jawans have been admitted at the BSF Hospital here.
"We have issued an advisory to the BSF hospital to take samples of all the BSF personnel at the Lyngkhat border outpost," Director of Health Services (MI) Dr Aman War told .
Since the detection of the first patient on April 13, a total of 72 COVID-19 cases have been registered in the state.
One person has succumbed to the disease so far, and 43 others have recovered.
Meanwhile, officials in Ri Bhoi said, the 48-hour curfew clamped on a few villages in the district, along the Meghalaya-Assam border, will continue to remain in force till 9pm on Sunday.
The curfew has been imposed as part of the government's measures to curb the spread of the disease in the state, the officials said.
The night curfew imposed from 10 pm till 5 am across the state has been extended till July 13, a senior home official said. JOP MM MM