Despite rules requiring people to share their results with authorities, many aren't doing so. This means the country’s already patchy testing data is even less accurate and that future clusters may go undetected.
Residents in four districts would be tested over the next 24 hours while other districts would be tested the next day, the Tianjin government said.
The Ministry of Health also announced that 42,818 doses of the COVID-19 vaccine were given in the past 24 hours. The total number of doses provided up to Friday stands at 21,502,582 with a rate of vaccine distribution of 217.41 doses per 100 people.
The ministry reported 175 new cases over the past day, bringing Iran's number of confirmed cases during the pandemic to more than 7,230,000. Iran's officially registered death toll stands at 141,318.
MoHAP also noted that an additional 1,674 individuals had fully recovered from COVID-19, bringing the total number of recoveries to 924,192.
"COVID is not over yet. I have directed all concerned to be alert and strengthen surveillance," Health Minister Mansukh said on Twitter. "We are prepared to manage any situation."
Mansukh Mandaviya announced the new rule in Parliament, where he also urged state governments to increase surveillance for any new coronavirus variants and send samples of all positive cases to genome sequencing laboratories.
Passengers from those countries would be put under quarantine if they showed symptoms of COVID-19 or tested positive, Health Minister Mansukh Mandaviya said.
The health ministry also reported 3,658 recoveries and 5 deaths due to COVID-19 complications. The ministry expressed its sincere condolences to the families of the deceased and prayed to Almighty Allah for the speedy recovery of the infected cases.