Britain has imposed sanctions on 18 more Russian oil tankers and four liquefied natural gas (LNG) tankers in what the government said amounted to the largest move against Moscow's "shadow fleet" circumventing restrictive measures by the West following Moscow's unprovoked invasion of Ukraine. "18 more shadow fleet ships will be barred from U.K. ports and unable to access world-leading British maritime services, bringing the total number of oil tankers sanctioned to 43," the government said in a statement. It said the oil tankers targeted by the latest sanctions are estimated to have hauled $4.9 billion-worth of oil over the past year. Russian gas company Rusgazdobycha JSC was also placed under sanctions, the statement said. "I have made it my personal mission to constrain the Kremlin, closing the net around [Russian President Vladimir] Putin and his mafia state using every tool at my disposal," the statement quoted Foreign Secretary David Lammy as saying.