Authorities found several explosive devices across a Maryland park over the weekend, prompting the park’s closure.

In a statement on Monday, the Prince George’s county fire department said that its bomb squad responded to Fort Washington Park after “several explosive devices were located”, prompting the US Park Police to close the approximately 341-acre site.

Officials said five devices were initially discovered and “rendered safe before operations were suspended after sunset”, adding: “This morning, additional explosive devices were located.”

“The bomb squad is on scene working to render the devices safe. A joint investigation with members of the PGFD fire marshal’s office along with the office of the Maryland state fire marshal, the ATF, the FBI, and the US Park Police is underway and ongoing,” PGFD added.

Photos posted online showed bomb squad officials suiting up at the scene, as well as what appeared to be several pipe bombs lying on the ground among leaves and rocks.

“There is no current threat to the public. If members of the public should come across a device similar to those pictured, do not touch the device. Leave the area and dial 911,” PGFD said.

The park remains closed as of Monday, according to the National Park Service.