BURLINGTON, Vt. — The Vermont Health Department is warning street drug users about an especially deadly strain of heroin that is circulating in several parts of the state, including central Vermont and the Northeast Kingdom.

Emergency responders reported that at least 10 people overdosed over the weekend and it took more than one dose of naloxone to revive them.

The state says bags of heroin, possibly laced with fentanyl and stamped “Game of Thrones,” appear to be connected to at least some of the overdoses. Fentanyl is up to 50 times stronger than heroin.

Health Commissioner Dr. Harry Chen is urging people who use street drugs or those who know someone who does, to be aware of the danger.

The state is also urging people to never use drugs alone.