By CBS Baltimore Staff

ADELPHI, Md. (WJZ) — At least 11 people were sickened by carbon monoxide during a church service in Prince George’s County over the weekend, officials said.

Crews were called to a property in the 3000 block of Buck Lodge Road on Sunday for a report of people unconscious. When they got to the scene, they found a group of 25 to 30 people inside a building where a church service was happening. Everyone was conscious.

READ MORE: Fire Breaks Out At Camp Airy For Boys In Thurmont, No Injuries Reported

Credit: Prince George’s County Fire Department

READ MORE: Hogan Laments 'Senseless Act Of Violence Against Law Enforcement' After Baltimore Officer Dragged By Car

EMS crews took seven people to hospitals for evaluation and treatment; multiple other people refused treatment or left the scene, the Prince George’s County Fire Department said.

On Monday morning, four more people went to a hospital with dizziness and vomiting, symptoms of carbon monoxide poisoning.

MORE NEWS: Baltimore Police Officer Still Fighting For His Life After Being Dragged By Car; Arrest Wednesday May Be Related

The fire department said crews found a natural gas leak and multiple gas-powered wall heaters in the building.

CBS Baltimore Staff