WASHINGTON — Sailors guarding the USS Cole when terrorists bombed it last month in Yemen did not have ammunition in their weapons and were instructed not to shoot unless fired upon, The Washington Post reported Tuesday.

Crew members told the newspaper that their "rules of engagement" prevent them from firing without obtaining permission from the ship's captain or another officer.

Suicide bombers in a small, explosives-laden boat approached the Cole while it was refueling Oct. 12 in Aden harbor and detonated the explosives, ripping a 40-by-40-foot hole in the steel hull. The blast killed 17 American sailors and injured 39.

Petty Officer John Washak told the Post said he was manning an M-60 machine gun shortly after the Cole was hit. Washak said he waved the weapon at a second small boat that was approaching, but a senior chief petty officer ordered him to turn the gun away.

Washak said he protested, fearing that the ship was still under attack. But even in the aftermath of the bombing, "with blood still on my face," he said he was told: "That's the rules of engagement; no shooting unless we're shot at."

Rules of engagement aboard a U.S. warship are set by its captain following Navy guidelines. Pentagon officials won't publicly discuss the specific rules in effect aboard the Cole. But senior officers said in congressional testimony that the ship filed a detailed security plan, which they think was followed.

"If we had shot those people, we'd have gotten in trouble for it," said Petty Officer Jennifer Kudrick, a sonar technician. "That's what's frustrating about it. We would have gotten in more trouble for shooting two foreigners than losing 17 American sailors."

A Navy spokesman Cmdr. J.D. Gradeck would not comment to the Post about the crew's accounts, citing the ongoing investigation.

The Post interviewed about 20 members of the ship's crew. Some said FBI investigators have told them the Cole may have been secretly boarded and surveyed by Islamic militants — possibly including one of the suicide bombers — as it passed through the Suez Canal a few days before the attack.

The FBI also has been questioning crew members about the behavior of the Yemeni pilot who guided the Cole into port; some described him as "agitated." Some crew members also said they thought Yemeni harbor workers acted suspiciously, the newspaper reported.