Ukraine has marked the 26th anniversary of the Chernobyl disaster with the construction of a new, safer shelter over the damaged nuclear reactor. Russian officials have apparently begun a probe into an oil spill in southeastern Siberia which was the result of illegal tapping of a state-owned pipeline. US energy giant Chevron has defended its use of shale gas fracking, by complaining to the European Parliament that a ‘campaign of misinformation’ was afoot to demonize exploration of the unconventional energy in Europe. According to this report, despite the controversy, Royal Dutch Shell is interested in the nascent UK shale gas market. Italian oil and gas group Eni has seen its underlying net profit in the first quarter increase 13% thanks to higher oil prices and the renegotiation of gas contracts in Russia. The world’s largest energy company, Exxon Mobil, has seen profits dwindle in the first quarter as a result of lower production. The Telegraph reports that Argentina has pledged it will pursue criminal and civil charges against British oil companies exploring off the Falkland Islands if they refuse to ‘justify their actions’ by a May 2 deadline. Russia apparently expects an underground nuclear test by North Korea within the next week.