About 50 people were tested, an unparalleled inquiry that comes in the wake of news reports about the war with Iran and the U.S. military’s diminished stocks of munitions.

U.S. government investigators have taken the extraordinary step of subjecting roughly 50 members of the U.S. military’s Joint Staff to polygraph tests over leaks to journalists, including about how the Iran war has created a shortage of crucial munitions, according to officials briefed on the move.

The investigators asked military officers and civilian employees on the Joint Staff if they disclosed classified information to members of the press, and about whether they provided information about diminished U.S. munitions stocks.

The polygraph tests were conducted in August after a flurry of news reports detailed diminished stocks of crucial munitions, including of long-range missiles and Patriot interceptors. The show of force appeared aimed at not just ferreting out anyone who may have shared information, but intimidating others who might do so in the future, according to people with knowledge of the effort.

Between 1,500 and 2,000 officers and officials work for the Joint Staff, which coordinates operations, policy and war plans with combatant commanders around the world.

In a statement, Pentagon spokesman Sean Parnell said that the department “does not comment on internal personnel or investigative matters but takes all leaks of classified national security information extremely seriously and investigates accordingly.”

“Securing classified information is critical to ensuring the security of the United States and of our troops deployed around the world,” he added.