A Trafford primary school was broken into as children, parents and staff attended a leavers' assembly.
St Monica's RC Primary School on Woodsend Road South in Flixton was targeted on Friday afternoon.
A member of staff confirmed that phones, keys and a laptop had been stolen during the raid.
They told the Manchester Evening News the entire school was in a leavers' assembly when someone managed to get into the infants' building.
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The crook ransacked several classrooms, as well as an office, escaping with property belonging to both the school and staff.
It is believed the break-in happened at some point between 2pm and 3pm.
St Monica's is in the process of reporting the theft to police.
Anyone who saw anything or anyone acting suspiciously, or who has any information relating to the break in, is asked to contact the school or GMP.
