The alarm was triggered at Fort Hood base in Texas, and police responded to an emergency call at around 3.50pm (9.30pm BST).
The alarm was later confirmed to be false, and police confirmed no gunman was on the loose.
The police commented on the incident, stating: “Upon investigating, it was determined there was no emergency.
“The 911 caller reported the incident upon hearing an internal emergency alarm indicating an active shooter.
Upon investigating, it was determined there was no emergency
Police spokesman
“Police cleared the building and found no emergency.
“Investigations revealed that the building alarm had been inadvertently activated at which time the system was reset.”
Fort Hood has dealt with a number of shooting rampages, including in 2009 when a gunman opened fire in the Soldier Readiness Centre, killing 13 individuals and injuring another 32.
The shooter was named as Nidal Malik Hasan, a US Army Major, who was convicted of 13 counts of premeditated murder in 2013, and sentenced to death.
In 2014, a shooting occurred across numerous locations on the base, resulting in the death of three people, along with 16 people being injured.
The gunman was later identified as Ivan Lopez, an Iraq War veteran, who died of a self-inflicted gunshot wound.
The base is located in Killeen, Texas, and houses close to 65,000 soldiers and family members.
