Manipur on May 21 recorded highest single-day spike of 16 new cases taking the number of infected to 25 in the state.
According to health sources, all had returned from other states.
Manipur has now 23 active cases, they further said.
Among the positive cases, two were from New Delhi and the rest were from a group that came from Chennai. All of them were now admitted in COVID Care facility of District Hospital Churachandpur.
On May 20, 405 tests were done at VRDLs of RIMS (205) and JNIMS (200).
In view of the rapid rise in the number of active cases, the government is taking up all possible control measures including strict containment and contract tracing.
Earlier, a woman and her daughter, who came back from New Delhi, were reported COVID-19 positive on May 19.
Manipur was COVID-19 free from April 14 after the first two patients were declared free from the virus.