Two men were arrested Sunday in what Holden police called the largest drug bust in the town’s history.

David Rowland, 29, of Stonington was charged with possession of a firearm by a felon, violation of conditions of release and unlawful possession of scheduled drugs, while 28-year-old Alex Hanna of Penobscot was charged with unlawful possession of scheduled drugs.

Rowland and Hanna were pulled over for what Holden police called a routine traffic stop when officers discovered a gun, cash, heroin, Xanax and fentanyl. The drugs were worth an estimated $45,000.

“To see that degree, that amount, 216 grams of fentanyl. We are talking about a pretty significant amount of fentanyl and that’s a very dangerous drug,” Holden Police Chief Chris Greeley told ABC affiliate WVII.

The investigation is ongoing, and police said more charges are expected.