Israel has discovered a previously unknown variant of Covid-19 – a combined variety of the Omicron sub-variants BA.1 and BA.2 – its Ministry of Health said in a statement on Wednesday.

Two such cases have been confirmed so far by the authorities. “This strain is not yet known in the world, and the verifications were discovered thanks to the PCR test performed at Ben Gurion Airport in Israel,” the Ministry said over Twitter.

It added that those infected displayed “mild symptoms” including fever, headaches and muscle ailments. However, they “did not require a special medical response”. The Ministry will continue to monitor the situation and provide updates as needed, the statement further said.

The World Health Organisation has not responded to Israel’s claim yet.

BA.1 and BA.2 are sub-variants of Omicron. The WHO had earlier noted that while the BA.2 sub-variant is more transmissible than BA.1, there is no difference in severity. However, there is little information available on the new variant discovered in Israel so far.

Salman Zarka, the chief Covid-19 officer in the country, has dismissed the new variant as a matter of serious concern. “The phenomenon of combined variants is well known… At this point, we’re not concerned about (the new variant leading to) serious cases,” Zarka was quoted as saying by Times of Israel.

Health Ministry Director-General Nachman Ash said while the origin of the variant was unknown at the moment, it may have emerged in Israel. “It’s likely that they were infected before boarding the flight in Israel. The variant could have emerged here. We don’t know what it means yet,” the Times quoted him as saying.