Five persons, including four females, have tested positive for novel coronavirus, taking the tally to 93, an official said on Wednesday.
The cases were confirmed at Zoram Medical College (ZMC) on Tuesday night.
Three of the patients have returned from Maharashtra, while two others have returned from Delhi recently.
Two patients belonged to Saitual district and one each from Aizawl, Lawngtlai and Serchhip districts, he said.
All the patients aged between 18-37 are out of danger, government officials said.
According to the officials, a total of 669 samples were tested at ZMC on Monday and Tuesday of which 51 came out as positive on Wednesday, which was the highest single-day count in the state since the first case was detected on March 24.
There are 92 active cases in the state including 48 males and 44 females and they are currently undergoing treatment at ZMC and other COVID-19 care centres across the state.
The first patient, who tested positive on March 24, recovered and was discharged from ZMC on May 9.
Meanwhile, a bulletin issued by ZMC said that more than 200 samples were tested on Wednesday and the results were awaited.
At least 7 people, suspected to be infected with Covid-19, have been admitted in the medical college on Wednesday, it said.
ZMC is the dedicated Covid-19 treatment centre in the state.
An official said that an automated RNA extractor machine was airlifted from Kolkata on Wednesday to expedite the testing process.
Two RT-PCR machines are currently operational at ZMC and it is expected that about 1,000 samples will be able to test in a day with the help of automated RNA extractor.