Police are appealing for witnesses to a burglary at a school in Irene Avenue, Lancing, at 10.10pm on Saturday, July 6.
Officers attended and arrested a 20-year-old man from Sompting, a 15-year-old boy from Shoreham and a 16-year-old boy from Lancing, on suspicion of burglary.
They were all questioned and bailed until Tuesday, 13 August while investigations continue.
PC Robert Luff said: “We are asking members of the public to be vigilant of anyone acting suspiciously and make sure their premises are secured safely at all times.”
Any witness or anyone with information is asked to call 101 quoting serial 1525 of 6/7. Alternatively, call the independent charity Crimestoppers anonymously on 0800 555 111.