Portland police arrested a man on drug trafficking charges Sunday, the same day the department warned residents that five people in the city had overdosed on contaminated heroin.

It is unclear if the drugs seized during the arrest are connected to Sunday’s overdoses, police say.

Gregory Waterman, 35, a transient of Portland, was arrested on charges of unlawful trafficking in scheduled drugs and unlawful possession of methamphetamine, police spokesman David Singer said in a press release.

According to police, Waterman possessed 20 grams of fentanyl, 12 grams of methamphetamine and more than $1,700 in cash at the time of his arrest.

The arrest was made after police stepped up patrols based on information that a dangerous batch of opioids was being distributed and used in Portland, Singer said.

Five people overdosed on Sunday after taking heroin contaminated with a type of animal tranquilizer, which, if injected, can cause necrotic wounds, serious injury or death. No fatalities were reported.

An investigation into the overdoses is ongoing and it is not certain if they are connected to the drugs Waterman had when he was arrested, Singer said.