CINCINNATI (AP) — An anti-heroin overdose coalition in the Cincinnati region has issued a warning after a sudden spike in suspected drug overdoses.

The Hamilton County Heroin Coalition issued the warning after authorities reported that emergency responders were called to 23 suspected overdoses between 6 a.m. Friday and 6 a.m. Saturday. The coalition suggested drug users follow protective measures, including carrying extra doses of the overdose-reversal drug naloxone, not using drugs alone and avoiding mixing drugs.

The coalition’s alert didn’t specify how many deaths might be attributed to the latest spike in overdoses.

Much of Ohio has been experiencing overdose surges since about April, with spikes tending to occur on weekends.

The Hamilton County coalition includes public and private health providers, elected officials and police and firefighters.