An explosion occurred Wednesday near a Covid-19 test centre in the Netherlands, shattering windows but causing no apparent injuries, police said.
"Near the local health service's testing centre in Bovenkarspel, an explosive went off at 6.55 am. Police are investigating. The perimeter has been sealed off," the police said in a statement.
A bomb squad was sent to determine whether any explosive material remained at the scene, public television network NOS reported.
In January a Covid testing centre was set on fire in the Dutch village of Urk as protests broke out over the start of an overnight curfew in the Netherlands introduced as part of measures intended to rein in the virus.
The Netherlands suffered several nights of rioting, the most violent the country has seen in decades.
A court last week ordered the government to immediately lift the nationwide curfew, ruling that the government had wrongly used emergency powers to bring it into force.
Wednesday's explosion was not the first case of suspected violence linked to the pandemic.
In January, a man was arrested in Wales after a suspect package was sent to a Covid-19 vaccination production site, forcing a partial evacuation.
According to a report published Tuesday by a health NGO, health workers battling the coronavirus were subjected to more than 400 acts of violence related to Covid-19 worldwide in 2020.
The Safeguarding Health in Conflict Coalition unveiled an interactive map that shows 1,172 violent acts and attacks occurred against health workers or facilities last year -- "a minimum estimate" according to the NGO.
More than a third (412) of the acts are directly related to Covid-19, it said, citing several examples including in Mexico, where a nurse was attacked and injured by a group accusing her of spreading the virus.