Of the fresh cases, five were reported from Dimapur and four from Kohima.
"Out of the 115 samples tested, nine more returnees from Chennai tested COVID-19 positive," the minister tweeted.
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.
A total of 36 cases were found in Dimapur district, followed by 17 in Kohima and five in Tuensang.
No case was reported from eight other districts of the state, an official said.
Nagaland reported the first COVID-19 case on May 25, and since then, there has been a surge in the number of infected people with migrants from other parts of the country returning home.
The Nagaland government has not counted a person from the state, who tested positive for coronavirus on April 12 in Assam after a private hospital in Dimapur referred him to Guwahati for treatment. He later recovered from the disease. NBS BDC BDC