The U.S. on Wednesday imposed sanctions on four firms operating in Venezuela's oil sector and designated four additional oil tankers, which the U.S. accuses of being part of a shadow fleet serving Venezuelan President Nicols Maduro's government, as blocked property. The action is part of the Trump administration's monthslong pressure campaign on Maduro. U.S. forces also have seized two oil tankers off Venezuela's coast, are pursuing another and have conducted a series of deadly strikes on alleged drug-smuggling boats in the Caribbean Sea and eastern Pacific Ocean. A set of strikes announced Wednesday increased the death toll from the attacks to at least 110 people since early September. And in a new escalation marking the first known direct operation on Venezuelan soil, the CIA carried out a drone strike last week at a docking area believed to have been used by drug cartels. The latest sanctions from the Treasury Department's Office of Foreign Assets Control target ships called Nord