The Omicron variant of the coronavirus has spread in a dozen Iranian provinces, bringing confirmed cases to 43, the health ministry announced on Thursday.

The head of Iran’s taskforce to combat coronavirus, Hamid Souri, has said that the PCR tests Iran uses may not be enough to detect the new variant.

World Health Organization Director-General Tedros Adhanom Ghebreyesus has warned that Omicron could lead to a “tsunami” of Covid-19 cases, because it is more transmissible and is circulating around the globe at the same time as the Delta variant.

Iran was the second country after China where the coronavirus spread in in early 2020 and Covid-19 became an epidemic, but the government was slow to admit the crisis and act to contain it, leading to the worst Covid crisis in the Middle East.

Iran has announced that it has closed all its land and sea borders to non-Iranians for 15 days, but air travel is still ongoing except from eight African and four European countries, namely England, France, Norway and Denmark.

A senior official of Iran’s national Coronavirus headquarters says the new variant will be the dominant type of Covid-19 in Iran in the coming weeks.

Iran, which confirmed the first Omicron case on Sunday, December 19, is one of the worst hit countries in the region by more than 131,000 officially announced deaths since February 2020.