Police are investigating the theft of a cache of weapons south of Perth.

Eleven rifles and two shotguns were stolen from the home of a licensed firearms dealer in Rockingham on Monday evening.

Offenders forced entry to the home and a gun safe before taking off with the weapons.

Detectives are asking for help from the public to identify those involved in the theft and to find the firearms.

Anyone with information is asked to call Crime Stoppers on 1800 333 000 or report online at crimestopperswa.com.au.