Two more Navy officers were fired after a series of deadly warship accidents in the Pacific this summer involving the 7th Fleet, a senior U.S. defense official confirmed Monday to Fox News.

The firings of Rear Adm. Charles Williams, commander of Combined Task Force 70, and Capt. Jeff Bennett, commodore of Destroyer Squadron 15, now bring the total number to seven U.S. Navy officials who received punishment for the crashes of the USS Fitzgerald and USS John S McCain, which left 17 sailors dead.

Four accidents have occurred in the Pacific since late January.

The majority of ships operating in the fleet weren’t certified to conduct basic operations at sea related to war fighting, according to U.S. Navy records released this month.

As of late June, eight of the 11 cruisers and destroyers in the 7th Fleet, and their crew members, weren’t certified by the U.S. Navy to conduct “mobility seamanship,” or basic steering of the ship, according to U.S. Navy records provided to two House Armed Services subcommittees.

The Navy also said that seven of those ships had expired training certification in the areas of cruise missile defense and surface warfare, which test a crew’s ability to defend a ship or to conduct attacks.

Last month, the Navy said it would review the 7th Fleet's performance, including personnel, navigation capabilities, maintenance, equipment, surface warfare training, munitions and certifications.

Navy Adm. John Richardson, the chief of naval operations, said the review will be conducted with the help of the Navy's office of the inspector general, the safety center and private companies that make equipment used by sailors.

Richardson is set to testify before Sen. John McCain, R-Ariz., the chairman of the Senate Armed Services Committee, on Tuesday. The USS John S McCain is named for the senator’s father and grandfather, naval commanders who served during World War II.

Fox News' Jennifer Griffin and the Associated Press contributed to this report.