Authorities at Schipol airport in Amsterdam had tested more than 600 passengers from the two flights that had arrived on Friday.
Some 61 cases of Covid in total were found – 13 (more than a fifth) of them the omicron variant, which is feared to be extremely contagious compared to previous variants.
However, experts do not yet know if the omicron variant causes more or less severe Covid compared to other variants.
Dutch health minister Hugo de Jonge told a press conference in Rotterdam: “It is not unlikely more cases will appear in the Netherlands.
“This could possibly be the tip of the iceberg.”
The Netherlands is set to go into a new lockdown later today, that had been planned prior to the discovery of the omicron variant in due to a spike in cases driven by the delta variant.
The discovery of omicron, dubbed a “variant of concern” last week by the World Health Organisation (WHO), has sparked worries around the world that it could resist vaccinations and prolong the pandemic that has gone on for nearly two years.
It was first discovered in southern African nations, and has now been detected in the UK, Germany, Italy, the Netherlands, Denmark, Belgium, Botswana, Israel, Australia and Hong Kong.
Many countries have banned flights from at least seven nations in southern Africa in attempts to curb the spread of the variant.
The return to some travel restrictions has seen financial markets plunge earlier this week over fears that the global economic recovery will be delayed further.