Four persons, including a passenger who returned from the UAE, tested positive for COVID-19 in Tamil Nadu on Tuesday. One person each from Chennai, Coimbatore and Krishnagiri, tested positive. A total of 10 persons were discharged, while 40 persons were currently under treatment for COVID-19 across the State. Of the total active caseload, Chennai accounted for nine. A total of 3,766 samples were tested in the State.