The Hague, Nov 29 : The Dutch Health authority has said it has found 13 cases of the new Omicron coronavirus variant among passengers on flights from South Africa. The cases were identified among 61 passengers who tested positive for coronavirus, the National Institute for Public Health and the Environment (RIVM) added in a statement. In an ongoing sequencing study, the new coronavirus variant B.1.1.529, or Omicron, first reported in South Africa, has been identified in 13 of the positive tests, said the RIVM. The investigation has not yet been completed and the new variant may be found in more test samples, according to the Dutch Health authority. The RIVM called on returning travellers from Omicron-risk countries, including South Africa, Botswana, Malawi, Lesotho, Eswatini, Namibia, Mozambique and Zimbabwe, to get tested if they have returned since November 22, even if they have no complaints, Xinhua news agency reported. On Friday, 624 passengers from South Africa were tested for coronavirus. Of them, 61 received a positive test result. The Netherlands on Friday suspended flights from southern African countries in an effort to keep out the new and potentially more transmissible variant. Health Minister Hugo de Jonge said on Sunday that he did not rule out the possibility of additional containment measures, which will depend on the seriousness and contagiousness of the new variant, about which little is known yet. /IANS