There have been at least 50 explosions outside homes and company premises in Rotterdam so far this year, compared with 49 in 2022 as a whole, according to regional broadcaster Rijmond.

Last week alone there were two explosions outside homes on the Crooswijkseweg and on Friday night there were two other blasts in the city.

Police have also arrested teenagers aged 14 and 15 who were placing explosives in a doorway on the Van Speykstraat, where there have been several earlier incidents. They were picked up following camera surveillance.

The city’s police told the Telegraaf it is a miracle no-one has been hurt in the explosions, which are mainly thought to be linked to drugs wars.

Last month Rotterdam mayor Ahmed Aboutaleb said the wave of attacks was linked to the number of drugs seizures at the city’s port, which had intensified rivalries between drugs gangs.

A spokesman for the mayor has described the situation as ‘extremely worrying’, particularly the ease with which the gangs have moved into exploiting young teenagers.

‘It is concerning that there are parents who have no control over their children, who in turn are heading off in the middle of the night to plant firebombs,’ the spokesman said.

Gangs like to use younger teenagers because they are less likely to face serious punishment if caught. They can also be lured into the underworld with the promise of easy money.

Rotterdam has set up several schemes to try and keep youngsters out of the clutches of drugs gangs, the NRC reported.