KUALA LUMPUR, Dec 16 — Malaysia has encountered its second case of the Covid-19 variant of concern dubbed Omicron, which the Health Ministry said was detected in an eight-year-old Malaysian girl who arrived from Nigeria.

The ministry said the Omicron infection was confirmed via genotyping assays that the Institute of Medical Research conducted on the polymerase chain reaction (PCR) Covid-19 tests performed on the girl and her family who arrived on December 5.

Malaysia reported its first confirmed case of Omicron infection on December 3, which was detected in a foreign student who arrived in Malaysia on November 19.

Omicron has caused concern among global health authorities due to its high number of mutations that could allow it to bypass the immune response accorded by existing vaccination regimes or previous Covid-19 infection.

The ministry added that the girl reported a negative PCR test prior to departing Lagos, Nigeria, with her mother and sister.

"The case and her family members underwent the Covid-19 RT-PCR test upon arrival at KLIA,” the ministry said, adding that her test returned a positive result.

"They were then issued a surveillance order under Section 15 of the Prevention and Control of Infectious Diseases Act and ordered to undergo home quarantine.”

Close contacts of the girl also included her father, who arrived ahead of his family, and a taxi driver who drove them from the airport, the ministry said.

It added that both have so far tested negative for Covid-19 infection but remain under observation.

Other contacts include 35 passengers on the flight seated in the vicinity of the family, but all have also tested negative twice; once on arrival and again after five days.

The ministry added that it also conducted further PCR-based assays on another 18 cases that possibly involved the Omicron variant, the results of which were expected tomorrow.