The blast in Bovenkarspel early on Wednesday morning shattered windows but caused no injuries, police from the province of North Holland said in a statement.
“The explosive must have been placed there”, police spokesman Menno Hartenberg said,
Hartenberg said that something metal had caused the blast.
“We don’t know yet exactly what exploded, the explosives experts must first investigate”,he added.
Officers have cordoned off the area as they carry out investigations.
All Wednesday morning test appointments in Bovenkarspel have also been cancelled.
The region around Bovenkarspel is currently suffering one of the Netherlands’ worst COVID-19 outbreaks, with 181 cases per 100,000 inhabitants, compared with around 27 per 100,000 nationally.
At least one hospital has been forced to send patients to other provinces due to lack of space in its intensive care units.
The blast follows worst unrest the Netherlands has witnessed in decades, with many angered by strict restrictions aimed at containing the COVID-19 pandemic.
Earlier this year, the government introduced a night-time curfew, the first to be implemented in the Netherlands since World War II.
The measure went into effect on January 23 and led to several days of rioting.
The protests gripped several cities and saw rioters torch a COVID testing centre in Urk, a northern village.
Police clamped down and hundreds of rioters were arrested. Many have already been sentenced by Dutch courts.
The curfew is in effect from 9pm to 4:30am daily, and is due to expire on March 15, two days before general elections.
The curfew is part of a strict lockdown in which bars, restaurants and non-essential shops have been closed for months.
Wednesday witnessed the first easing of lockdown measures in several months, with hairdressers reopening and non-essential stores allowed to accept a small number of visitors by appointment.