Windows in the building were destroyed after the blast in the town of Bovenkarspel on Wednesday morning, police said.
Nobody was injured, but police were still investigating what had caused the early-morning blast.
Dutch broadcaster NOS reported that police suspected a deliberate pipe explosion outside the test centre shortly before 7am.
The town of Bovenkarspel, shown on this map of the Netherlands, saw an explosion at a Covid-19 testing facility today
While the suspicion of a deliberate attack is not confirmed, it comes weeks after several consecutive nights of rioting against lockdown measures in the Netherlands.
Rioters set fire to a testing facility in the fishing village of Urk during the late-January unrest which followed the introduction of a nationwide curfew.
While Dutch infection rates have fallen from their winter peak, they are still very high in the so-called safety region of North Holland (North) which includes Bovenkarspel.
The region saw 360 new cases on Tuesday, representing a high figure of 54 infections per 100,000 people in the previous 24 hours.
Across the Netherlands, the figure was 23 per 100,000, making the region one of the country’s major hotspots.
More than 14 per cent of tests came back positive in the region, compared to a figure of nine per cent across the Netherlands.
More to follow.
The mystery explosion at a testing centre on Wednesday comes weeks after several consecutive nights of rioting against lockdown measures (file photo)