A cardboard box with a flicking green light set off a bomb scare on Thursday when it was thrown on to the pavement outside the Royal Thai Police headquarters in Bangkok.

The box was dumped by a man on a motorcycle who fled the scene. He was wearing a cap and a protective mask. The man was described as having been dressed in a yellow shirt and black pants, with black sneakers. He was also carrying a side pack.

Members of an Explosive Ordnance Disposal unit opened the box and found a fruit juice carton inside it. The carton had a device producing a flicking green light inside it. A barricade was briefly set up at the scene.