SINGAPORE --The U.S. 7th Fleet says Navy and Marine Corps. divers have joined the search for 10 missing sailors and will access flooded compartments on the USS John S. McCain, which is docked at Singapore's Changi Naval Base.

It says the sea-based search by aircraft and ships from the U.S., Singapore and Malaysian navies was continuing for a second day Tuesday east of Singapore, where the McCain and an oil tanker collided at daybreak Monday at an approach to a busy shipping lane.

"Equipped with surface supplied air rigs, divers will access sealed compartments located in damaged parts of the ship," the 7th Fleet's statement says. "Additionally, they will conduct damage assessments of the hull and flooded areas."

The U.S. Navy guided-missile destroyer USS John S. McCain is seen in Singapore waters on Mon., Aug. 21, 2017. Reuters

The U.S. Navy ordered a broad investigation into the performance and readiness of the Pacific-based 7th Fleet after the collision between the guided missile destroyer and oil tanker.

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Aircraft from the amphibious assault ship USS America and ships and aircraft from the navies of Malaysia and Singapore were taking part involved in the search.

The McCain's crew was trying to empty compartments that flooded when the collision ruptured the ship's hull at its waterline, the 7th Fleet said in a statement.

It was the second major collision in two months involving the 7th Fleet. Seven sailors died in June when the USS Fitzgerald and a container ship collided in waters off Japan.

"It is the second such incident in a very short period of time - inside of three months - and very similar as well," Navy Adm. John Richardson, the chief of naval operations, told reporters at the Pentagon. "It is the last of a series of incidents in the Pacific fleet in particular and that gives great cause for concern that there is something out there we are not getting at."

Richardson ordered a pause in operations for the next couple of days to allow fleet commanders to get together with leaders, sailors and command officials and identify any immediate steps that need to be taken to ensure safety.

A broader U.S. Navy review will look at the 7th Fleet's performance, including personnel, navigation capabilities, maintenance, equipment, surface warfare training, munitions, certifications and how sailors move through their careers. Richardson 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.

There was no immediate explanation for the collision. The city-state of Singapore, at the southern tip of the Malay Peninsula, is one of the world's busiest ports and a U.S. ally, with its naval base regularly visited by American warships.

There was no indication the collision was intentional or that cyber intrusion or sabotage had occurred but the review will consider all possibilities, Richardson said.

The McCain had been heading to Singapore on a routine port visit after conducting a sensitive freedom-of-navigation operation last week by sailing near one of China's man-made islands in the South China Sea. The collision between the guided missile destroyer and the Alnic MC oil tanker ripped a gaping hole in the destroyer's hull on its port side aft, flooding adjacent compartments including crew berths, machinery and communications rooms.

It happened about 4.5 nautical miles from Malaysia's coast, but the McCain was able to sail on to Singapore's naval base. Malaysia's Maritime Enforcement Agency said the area is at the start of a designated sea lane for ships sailing into the busy Singapore Strait.

Janes, a defense industry publication, estimated the hull breach was 10 feet wide. The 7th Fleet said damage control efforts prevented further flooding.

Five injured sailors were taken to a hospital in Singapore for medical treatment.

One of the injured sailors, Operations Specialist 2nd Class Navin Ramdhun, posted a Facebook message telling family and friends he was OK and needed surgery for an arm injury. He told The Associated Press in a message that he couldn't say what happened. "I was actually sleeping at that time. Not entirely sure."

The Singapore government said no crew were injured on the Liberian-flagged Alnic, which sustained damage to a compartment at the starboard, or right, side at the front of the ship some 23 feet above its waterline. The ship had a partial load of fuel oil, according to the Greek owner of the tanker, Stealth Maritime Corp. S.A., but there were no reports of a spill.

Several safety violations were recorded for the oil tanker at its last port inspection in July, one fire safety deficiency and two safety-of-navigation problems. The official database for ports in Asia doesn't go into details and the problems apparently were not serious enough for the tanker to be detained.

The Navy last week said the Fitzgerald's captain was being relieved of his command and other sailors were being punished after poor seamanship and flaws in keeping watch were found to have contributed to its collision. An investigation into how and why the Fitzgerald collided with the other ship was not finished, but enough details were known to take those actions, the Navy said.

The McCain, based at the 7th Fleet's home port of Yokosuka, Japan, was commissioned in 1994 and has a crew of 23 officers, 24 chief petty officers and 291 enlisted sailors, according the Navy's website.

The destroyer is named for two decorated World War II admirals who were the father and grandfather of U.S. Sen. John McCain.