The two children were watching an adult light a fireworks display when the incident took place in Haaksbergen.
Police said they had arrested a man and opened an investigation.
On New Year’s Eve, the Dutch traditionally launch fireworks on the streets and in the gardens, a popular practice that causes many injuries.
The government has banned fireworks for the second year in a row to avoid overloading hospitals with the epidemic.
In 2019, more than 1,300 people were treated for injuries caused by fireworks.
Do you have images or information that could become news? Send us a message at 0744.882.200 on Whatsapp or Signal