KUALA LUMPUR, Malaysia — The collision between the USS John S. McCain and an oil tanker has exposed a long-simmering dispute between Singapore and Malaysia over which country should control a 60-meter (197-foot) wide guano-encrusted outcropping at the edge of the South China Sea.

Malaysia and Singapore both say the accident happened in their territorial waters because of the competing claims to Pedra Branca. Barely an island, the rocks are home to utilitarian structures including a communications tower meant to reinforce Singapore’s claim and lapped by waters often fouled by mini oil slicks in one of the world’s busiest shipping lanes.

Despite being devoid of charms, the islet is a major political and economic prize for both countries.

Singapore and Malaysia were quick to help when the guided missile destroyer and oil tanker Alnic MC collided early Monday while the U.S. ship was approaching Singapore on a routine port call. And both claimed to be the coordinator of the search and rescue effort for 10 missing Navy sailors.

Malaysia has deployed four warships, multiple boats and aircraft along with more than 500 personnel, while Singapore contributed five helicopters, five aircraft, more than 300 personnel including divers and numerous ships.

“The subtext of both Singapore and Malaysia’s search and rescue efforts is about asserting and staking their claims to the disputed areas,” said Eugene Tan, associate professor of law at the Singapore Management University.

The International Court of Justice awarded Pedra Branca — known in Malaysia as Batu Puteh, which also means white rock — to Singapore in 2008, but handed another rocky outcrop nearby to Malaysia. Earlier this year, Malaysia reignited the dispute with a fresh bid to review the court’s decision.

Relations between the two countries have often been prickly since they split in 1965 after a brief union following the end of British colonial rule over what was then called Malaya. Despite strong economic, social and security ties, relations are often influenced by economic rivalry and mistrust.

Located at the southern tip of peninsular Malaysia, Singapore is a speck next to its neighbor yet has flourished to become a regional economic powerhouse and a global financial center. Its position at the eastern end of the Malacca Strait, a key waterway for global trade, has given the predominantly Chinese city economic and strategic importance.

Muslim-majority Malaysia, despite its much larger population and land area, lags behind economically. It is rapidly developing its southernmost state of Johor, which faces Singapore, to vie for investment. Johor already has a large container port that has lured away clients from Singapore’s bustling port with lower costs, and a sprawling regional oil and gas complex is underway in the state.

The overlapping claims apparently haven’t hurt search and rescue efforts for missing sailors. Divers have found some remains in flooded compartments of the McCain, which is docked at Singapore’s naval base, but the Navy has not disclosed specifics.

“The top priority is the search and rescue. Jurisdiction issues should not overshadow the main priority. This incident should be seen as a test of cooperation, rather than conflict,” said Bridget Welsh, a visiting professor at John Cabot University. She said the two countries will eventually have to find a compromise.

Adm. Scott Swift, commander of the U.S. Pacific Fleet, has praised both countries for their help. At a press conference in Singapore on Tuesday, he dodged questions about which country is in charge, saying that the focus was on finding the sailors.

Malaysia’s fresh bid to reclaim Pedra Branca is partly driven by the islet’s strategic location as an important access point to the South China Sea, which is key to security and defense, said Tan of the Singapore Management University.

“Territory, in particular territorial waters, is another vital security and economic consideration. For both countries, ownership of Pedra Branca enables them to claim a larger territorial sea, adding to the fishery resources and seabed mining potential,” he said.

Tan said Malaysia’s move could also be useful for embattled Prime Minister Najib Razak and his ruling coalition to stir nationalism ahead of general elections, due by mid-2018. Najib is under pressure over a multi-billion-dollar financial scandal and faces his toughest test in the polls. His coalition won the 2013 polls but lost the popular vote for the first time to an opposition coalition.

It is unclear which country will oversee the investigation. Singapore has released maps to support its assertion that the collision happened in its territorial waters.

A senior official from Malaysia’s Marine Department, which is in charge of probing ship collisions, told The Associated Press that marine officials are waiting for further advice from the country’s mapping department.


Associated Press writer Annabelle Liang in Singapore contributed to this report.