Two men aged 56 and 33 have been arrested in Pwllheli on suspicion of interfering with motor vehicles.
Two people were reportedly seen trying to open car doors in the Cardiff Road and Potts Street areas on 11 August.
The men, from the Pwllheli area have been released on bail pending further investigations.
Inspector Iwan Jones said: “I would like to thank the community for reporting these incidents and for standing together in making Pwllheli a safe place to live work and visit.”