A U.S. naval blockade of the Strait of Hormuz went into effect Monday at 10 a.m. EST at the direction of President Donald Trump, but in a matter of hours, the blockade was breached without incident by at least four Iran-linked vessels, BBC reported Tuesday.On Monday, Trump said that he had instructed the U.S. Navy to “seek and interdict every vessel in international waters that has paid a toll to Iran,” and the U.S. military later said that the “blockade will be enforced impartially against vessels of all nations entering or departing Iranian ports and coastal areas.”However, ship tracking data analyzed by BBC Verify revealed that at least four Iran-linked vessels “crossed the Strait of Hormuz” without incident; two on Monday, and two overnight.“The Rich Starry, a tanker that is sanctioned by the United States under a different name, sailed through the strait overnight Monday,” CBS News reported, with the outlet having also analyzed ship tracking data. “The Elpis, another sanctioned tanker, sailed through the strait after the blockade began, having apparently come from the Iranian port of Bushehr, according to tracking data.”The Rich Starry is a U.S.-sanctioned Chinese oil tanker, and was the first vessel to breach the blockade since its implementation Monday morning. The Chinese government called the United States’ blockade "dangerous and irresponsible,” with Chinese President Xi Jinping warning that the world must not be allowed to “revert to the law of the jungle,” NBC News reported.Despite news organizations having analyzed tracking data, the outlets could not confirm whether or not the Iran-linked vessels had broadcasted false location reports using a tactic called "spoofing," which CBS News describes as a method to conceal a vessel's true location.Trump’s decision to respond to Iran’s partial blockade of the Strait of Hormuz with another blockade has baffled experts, including Karen Young, a senior scholar at the Center on Global Energy Policy at Columbia University, who told CNN on Sunday that Trump’s blockade would only exacerbate the increasing scarcity of oil.