Washington, D.C., park closed after WWI-era munitions were found — and more may be hidden there

Fort Totten Park in Washington, D.C., is closed after World War I-era munitions were discovered there this spring, and park officials say there may be more.

The Civil War-era fort, located three miles north of the Capitol, is fenced, blocked with cement barriers and bears “no trespassing” signs, the National Park Service said Thursday.

Two metal canisters were found in the park on April 18 after “unauthorized work conducted by an adjacent property owner pushed approximately 10 feet of soil onto NPS land,” the park service said.

One munition was a 75-mm projectile that was 3 inches in diameter and 11 inches long. The other was a Livens projectile that was 6 inches in diameter and 19 inches long.

“Initial assessment by Army experts indicated the 75-mm projectile did not pose a hazard and the Livens projectile contained an unknown liquid,” park officials said.

The items were transported and evaluated by the Army’s Materiel Assessment Review Board. However, initial testing of the liquid in the Livens projectile was inconclusive and it was taken to Aberdeen Proving Ground in Edgewood, Maryland, in August for additional testing, which indicated the Livens did not pose a hazard.

Additional testing determined that the 75-mm projectile contained only soil and the Livens projectile was filled 85% with liquid that was majority water and “0.0006%” acetophenone, a nonhazardous commercial chemical used in soaps and perfumes.

The NPS and the Army are seeking funding to conduct a comprehensive investigation at Fort Totten Park.

Visitors are urged to stay out of the area, and if anyone does encounter a munition, they should consider it dangerous, not approach or touch it, and call the police.

It’s not clear when the park may reopen.

Fort Totten was built as part of the Northern Defenses in the Civil War and was completed in 1863. It was named in honor of Brig. Gen. Joseph G. Totten, the former chief engineer of the U.S. Army, according to the National Park Service.

This article was originally published on NBCNews.com