Wellington County OPP say three men and one youth were arrested during a break-in in progress at a medicinal marijuana grow operation in Erin, Ont., northwest of Brampton, on Thursday.

Police were called to the Health Canada-authorized grow operation on Side Road 17 in Erin at 12:08 p.m. on Thursday, for a report of a break-in in progress.

Charges laid indicate the suspects were carrying firearms and wearing some sort of disguise.

Three men ranging in age from 19 to 26 as well as a 16-year-old boy from Brampton were arrested, police said.

They each face seven charges including break and enter, disguise with intent, conspiracy, and firearms offences.

All four suspects appeared in a Guelph bail court on Friday.

Anyone with information about this incident is asked to contact police at 1-888-310-1122, or Crime Stoppers at 1-800-222-8477 (TIPS).