Links between an out-of-control party in a small regional community south-east of Melbourne where police were forced to deploy capsicum spray and two assaults in a nearby park are being investigated by police.

The celebration, believed to be a joint 18th birthday party for two boys held at a hired hall, was being held on Saturday night on Rossiter Road in Koo Wee Rup.

Rossiter Road in Koo Wee Rup. Credit:Google Maps

Police were called to the premises about 9pm after receiving noise complaints. They spoke to the host of the party, giving him a warning to turn the music down.

But roughly an hour later they returned after partygoers were reportedly throwing bottles in the street.