All new patients had returned to the state from Chennai on May 22 by a Shramik Special train.
The train brought back 1,328 residents of the state, who were stranded in different parts of Tamil Nadu due to the lockdown.
"Out of 90 samples tested from Chennai returnees, six tested COVID-19 positive. All cases are from Dimapur," the minister said in a tweet.
The state recorded a surge in the number of cases with migrants from other parts of the country returning home.
A total of 31 patients are undergoing treatment at a COVID hospital in Dimapur, 13 in Chedema facility in Kohima and five in Tuensang hospital.
The Nagaland government has not counted a person from the state who tested positive for coronavirus on April 12 last in Assam after a private hospital in Dimapur referred him to Guwahati for treatment. He later recovered from the disease. NBS BDC BDC