The Christchurch Bus Exchange is closed after an incident about 3.15pm this afternoon.
A cleaner's hands have been injured after there was a small explosion in a coke type bottle.
This is the third such incident in Christchurch this afternoon and DS Mark Reid says that police are taking it very seriously.
The first was in the High Street Arcade and the other at Carlton Mill corner.
Specialist Search Groups and a bomb dog will clear the building before it can be reopened.
DS Reid asks that any suspicious sightings of people in those areas be reported to him immediately.
Anyone with information should call 363 7400.
Passengers are advised that buses are continuing to run and will bypass the Exchange. Passengers are advised to go to their next bus stop after the exchange to catch their bus home.