Iranian missile and drone strikes have inflicted at least $5 billion in damage on U.S. military bases across the Middle East, according to a sweeping Wall Street Journal investigation that offers the fullest public picture yet of what the war on Iran has cost American forces in the region.

The Journal's analysis, drawing on satellite imagery, Iranian military statements and interviews with U.S. officials, identified 274 damaged structures at 24 installations with an American military presence during the war's first six months.

The investigation found that Iran increasingly targeted buildings where American troops live and sleep, showing an improved ability to sequence attacks and strike with greater precision.

While the Pentagon has priced the damage to bases at a minimum of $5 billion, according to U.S. officials familiar with the matter cited by The Journal, a separate person briefed on the cost said the figure could reach as high as $15 billion.

The Center for Strategic and International Studies, which reviewed the Journal's findings on damaged buildings, estimated that reconstruction alone would top $4 billion, a figure that excludes replacing the equipment and systems housed inside.

Those repairs come on top of the war's overall cost, which stood at $47.1 billion as of Oct. 16, according to a document viewed by The Journal.

According to an Associated Press analysis, Iran's strikes on more than two dozen U.S. bases in the Middle East focused on early-warning systems before hitting aircraft and buildings, causing billions of dollars in equipment damage.

The AP independently verified damage to American targets using satellite imagery from multiple providers and spoke to four regional officials who were briefed or have firsthand knowledge of what was hit. The AP found that, through August, more than 115 drone or missile strikes claimed by Iran or Iranian-backed militias damaged or destroyed structures on 26 military bases and other sites with U.S. equipment.

The Journal also said the human toll has also mounted. More than 20 U.S. service members have died in activity related to the war since it began on Feb. 28, according to Defense Department data, and more than 400 were wounded before a temporary ceasefire collapsed in July. After that, the government stopped publishing casualty figures specific to the conflict.