The San Bernardino County Sheriff’s Department responded to Loma Linda University Children’s Hospital Wednesday evening following reports of a possible shooter.

By 8 p.m., the massive law enforcement presence that swarmed on the hospital was beginning to pack up and leave as the facility was being cleared and no threat was immediately discovered.

“Law enforcement is actively clearing Loma Linda Hospital,” the Sheriff’s Department wrote on social media. “At this time, no shots have been heard, and no one has been injured.”

Officials later said the initial reports of an active shooter stemmed from a “swatting call,” a dangerous and illegal prank in which a caller claims there is a life-threatening emergency at a specific location, leading to a large police response.

Earlier Wednesday night, the Sheriff’s Department released a statement via social media around 6:35 p.m. in which it said it was aware of reports of a “possible armed individual.”

Loma Linda University Health later confirmed that authorities had responded to the hospital as part of an “active investigation.”

Hundreds of law enforcement officers from the Sheriff’s Department and surrounding areas responded to the scene to assist with evacuations and clearing the large facility room by room.

Videos from Sky5 showed the vast law enforcement presence with dozens of police cruisers, multiple armed vehicles and heavily armed officers wearing tactical gear. Law enforcement helicopters were also flying over the active scene.

Around 7:45 p.m., many of those who had been evacuated for their safety were being allowed to return.

But the Sheriff’s Department urged the public to avoid the area if possible, as the investigation was still ongoing even with a reduced law enforcement presence still on scene. The area, officials said, would be reopening later Wednesday evening.

Potential patients were encouraged to visit other medical centers in the area, including Redlands Community Hospital in Redlands and Arrowhead Regional Medical Center in Colton.

The penalty for those caught orchestrating a swatting prank can range from misdemeanor or felony charges, jail time and heavy fines. That investigation remains ongoing.

Loma Linda is located about six miles south of San Bernardino and about 60 miles east of Los Angeles.