Hong Kong police are investigating after a blade was discovered between two seats on a Citybus double-decker, the second such case reported in recent days.

A male passenger alerted the driver of the route 37A bus, which travels from Pok Fu Lam’s Chi Fu Fa Yuen to Central, at about 5.20pm on Wednesday that the box cutter had been found on the upper deck.

Police officers boarded the bus when it stopped outside Pacific Place in Admiralty and seized the item. The box cutter measured about 13cm (5.11 inches), with a 1cm extendable blade. No passengers were injured.

The force classified the case as attempted wounding with intent. The Central district crime squad is investigating the incident.

A Citybus spokesman said the company was cooperating fully with law enforcement.

On Saturday, a woman travelling on Citybus route 15C was pricked by a sewing needle hidden in the back of a seat.