Letter bomb causes 'small explosion' at ING office in Amsterdam

View of an office building where a suspected letter bomb went off in the mail room, in Amsterdam. (Reuters Photo)

A letter bomb went off on Thursday at an office of ING Bank in Amsterdam, causing a "small explosion" in which no one was hurt, a spokeswoman for the bank said.

A series of letter bombs have been sent in the country this week, including one disarmed near Utrecht earlier on Thursday.

Police said an ambulance was sent to the ING building as a precaution after one person had inhaled smoke there.