More than two dozen people were hospitalized for suspected drug overdoses in Baltimore on Thursday, as rescue crews scoured alleys and homes in fear that there were more victims.

The crisis involved an unusually large number of patients in a city that has struggled with overdoses. Reporters for The Baltimore Banner working with The New York Times examined the city’s drug overdose crisis, the worst in the country, in a series of articles last year.

There were no fatalities reported on Thursday, but 25 people were hospitalized with suspected overdoses, according to an officer who answered the phone at the Baltimore Police Department’s Western District station early Friday and declined to give his full name. The hospitalizations were earlier reported by The Banner, which cited Lindsey Eldridge, a police spokeswoman.

The overdoses set off a large response by emergency medical workers, police officers, public health officials and state agencies, the day after Baltimore City Council members held their first public hearing on the city’s drug crisis. The Times/Banner investigation found that the crisis had been triggered by fentanyl but exacerbated by some treatment providers’ exploitative practices and city leaders’ failure to respond forcefully.

Officials have not said what type of drug was involved in Thursday’s overdoses, which remained under investigation, the city of Baltimore said in a statement.

The Baltimore City Fire Department initially responded to a report of an overdose in the Penn North neighborhood of West Baltimore around 9 a.m. When members of an emergency crew arrived, residents directed them to additional unconscious people, the fire chief, James Wallace, said in a news conference on Thursday afternoon.