Cash and jewellery were taken from a house at Ballamilligan, Mount Rule - the latest in a string of break-ins.
Police say another burglary was foiled by a householder in Vicarage Park, Douglas.
Inspector Derek Flint said: 'We were on scene very quickly, but despite an extensive operation, the offender made good their escape again.'
Police are leafleting homes urging people to get in contact if they see any suspicious behaviour.
Inspector Flint said: 'If it is something happening there and then - ring 999. The sort of stuff we are talking about is people up the side of houses, in places they shouldn't be, odd callers to the door etc.
'If it is something that has happened, and you think we should know about then call us on 631212.'
And he has repeated his warning about speculation on social media, stating: 'Remember the official Constabulary social media is the only place that you will get properly analysed fact on what is actually going on.'
Got a story? Contact Joanne on 340000 or email newsdesk@manx.net
twitter @jonewsiom