Parcels were stolen during a burglary at a Royal Mail depot in east Manchester.
It happened at the firm's Manchester East Delivery Office in Miles Platting on Wednesday night (September 17).
A large police presence was seen at the building on the corner of New Street and Canada Street at around 9pm.
Greater Manchester Police (GMP) have confirmed they were responding to reports of a burglary.
An eyewitness said a ladder could be seen 'sticking out of a window' of the building, with officers 'surrounding' it in case anyone was inside.
Royal Mail said it is believed a 'small number' of parcels were taken during the break-in.
A company spokesperson said: "We are assisting police with their investigation. Initial enquiries suggest only a small number of parcels were taken.
"We are working to identify the intended recipients and will contact those customers directly.”
No one has yet been arrested in connection with the incident, GMP said.
A spokesperson for the force said: "We were called at around 8:55pm on Wednesday 17 September after reports of a burglary at a premises on New Street in Newton Heath.
"No arrests have been made an our enquiries are ongoing."