A teenager has been arrested after he was spotted carrying a bag with explosive materials near the home of a plumber who has been the target of 10 bomb attacks in the last three months.

Security guards alerted police after the 19-year-old man was seen acting suspiciously in Gretha Hofstraatlaan in Vlaardingen on Tuesday evening.

The man dropped the bag and fled when police arrived, but was arrested soon afterwards following a helicopter search.

Bomb disposal experts examined the bag and found what police called an “explosive”, which was made safe at the scene.

Police would not say if the man was a suspect in the ongoing investigation into a series of bomb blasts against plumber Ron van Uffel, whose home and business premises have been targeted repeatedly since mid-December.

Van Uffel and his family went into hiding and his home and businesses were shuttered, but the council allowed the plumber to return to the house on January 19 after the explosions appeared to have stopped.

The latest explosion, the first for a month, happened in the early hours of Saturday at the plumber’s home, damaging a ground-floor window, RTV Rijnmond reported. It is not clear if he was in the house at the time.

Police have made five arrests so far in connection with the blasts. Three men from Rotterdam aged 17, 24 and 26 were arrested before Christmas, followed by a 19-year-old man from Delfzijl and a 30-year-old man from Rotterdam in early January.