Two US B-52 strategic bombers flew over the contested South China Sea on Wednesday, according to the US Pacific Air Force, the second such flight in 10 days despite China’s objections. “Two B-52H Stratofortress bombers took off from Andersen Air Force Base, Guam, and conducted routine training in the vicinity of the South China Sea on March 13 [Hawaii Standard Time], before returning to base,” a spokeswoman for the Pacific Air Force said in a statement released on Thursday. “US aircraft regularly operate in the South China Sea in support of allies, partners, and a free and open Indo-Pacific,” the statement said. “US Pacific Air Forces bombers have flown from Guam for more than a decade as part of US Indo-Pacific Command’s continuous bomber presence operations.” Meanwhile, the USS Blue Ridge, flagship of the US 7th Fleet also sailed through the South China Sea and anchored at Manila Bay on Wednesday, in a show of reassurance for the US-Philippine alliance in the region. When asked if his contingent had encountered the Chinese navy in the region, Captain Eric Anduze, commander of the USS Blue Ridge, said “all of our interactions were safe and professional”, vowing the US military would “sail, fly and operate wherever the law allows us to”. Sun Zhe, co-chair of the China programme at Columbia University, said the intention of the US in using B-52s was to restrain China in the South China Sea. “By dispatching strategic bomber *which is capable of carrying nuclear weapons* - instead of reconnaissance aircraft such as EP-3 - the US’s intention is very clear: to restrain China through flaring up the issue of South China Sea,” Sun said, “Beijing should remain vigilant.” Sun said the US military had increased the frequency of its close surveillance – in the air and at sea – on contested islands in recent years. Diao Daming, a US studies expert at Renmin University in Beijing, said the US military had been enhancing its presence in the South China Sea under the Trump administration’s Indo-Pacific strategy. But he dismissed suggestions that the US was pressing China on trade talks by sending the B-52s. “These are two different issues,” Diao said. “Beijing absolutely will not concede to any pressure from other issues.” Bonnie Glaser, an Asia security specialist at the Centre for Strategic and International Studies said the US military was now more willing to publicise its freedom of navigation operations. “The US is exercising it’s international right to freedom of navigation in the air and at sea,” Glaser said. “In the past, such operations were not always publicised.” Wednesday’s operation followed one on March 4, in which two B-52Hs conducted training flights from Guam, one to the East China Sea and one to the South China Sea. It also came as the US’ top diplomat accused China of blocking energy development in the South China Sea through “coercive means”, preventing Southeast Asian countries from accessing more than US$2.5 trillion in recoverable energy resources. Addressing top energy firm executives and oil ministers in Houston, Texas, on Tuesday, US Secretary of State Mike Pompeo criticised “China’s illegal island-building in international waterways”, insisting that it was not “simply a security matter”. China’s foreign ministry slammed Pompeo’s claims as “irresponsible” . Ministry spokesman Lu Kang said in Beijing on Wednesday that Beijing had started consulting Southeast Asian nations about resolving disputes in the South China Sea, and called on non-claimant nations to keep out of the discussions. “Nations in the region are capable of resolving and managing the disputes in their own ways,” Lu said. “Nations outside the region should refrain from stirring up trouble and disrupting the harmonious situation.”