NEW HAVEN, Conn. (AP) - New Haven officials are declaring a public health emergency after nearly 20 people overdosed on tainted heroin or cocaine and at least three died in the city and surrounding towns.

Officials issued the warning Friday. They said there have been up to 16 heroin or cocaine overdoses in New Haven since Thursday and several more in surrounding communities.

Two people died in New Haven and at least another died in another town. Officials said the numbers will likely rise.

Police are trying to determine if the powerful painkiller fentanyl or another substance is responsible.

State health officials said they're sending 700 doses of the overdose reversing drug Narcan to New Haven.

Gov. Dannel P. Malloy said the situation is dangerous and the state is working to address the overdose problem.