Five men, believed to be Irish nationals, have been charged and more than $70,000 worth of allegedly stolen property has been recovered after a spate of break-ins in north-west Sydney.

The five were arrested at an apartment block in Pennant Hills in a major police operation on Tuesday, following numerous reports of break-ins and thefts in The Hills, Ku-ring-gai and Ryde regions over the past few weeks, police said.

Items valued at more than $70,000 including luxury-brand watches, designer jewellery as well as vehicles and balaclavas allegedly used by the men have also been recovered, police said.

The charges included aggravated break and enter with intent, participating in a criminal group, possessing housebreaking implements, ​having goods suspected to have been stolen.

The men - aged between 19 and 22 - were refused bail and will appear in Hornsby Local Court on Wednesday.

AAP, Fairfax Media