Liberian law enforcement agents have burned some 4.2 metric tons of cocaine worth about $336 millionBy MARK MENGONFIA Associated Press and MARK BANCHEREAU Associated PressMONROVIA, Liberia -- Liberian law enforcement agents burned some 4.2 metric tons of cocaine worth about $336 million on Thursday, days after authorities announced the country’s largest-ever drug seizure and implicated senior police officials in the trafficking operation. Authorities said investigators identified officers who had allegedly helped escort the cocaine after it arrived in Liberia. Liberian authorities said last week they seized nearly 4 metric tons (8,818 pounds) of cocaine with an estimated “street value” of around $317 million, and detained two foreign nationals while investigating what they described as a sophisticated transnational trafficking network. Liberia's police and drug enforcement agency also burned 237 kilograms (522 pounds) of cocaine valued at more than $19 million that was seized in June at Roberts International Airport. According to the Global Initiative Against Transnational Organized Crime, at least 30% of cocaine destined for Europe now passes through the region, while local cocaine consumption, including of crack cocaine, has also been rising.