U.S. regulators didn\'t fully consider the 2010 oil spill in the Gulf of Mexico when deciding to go ahead with an offshore lease sale, environmentalists say. The Southern Environmental Law Center filed a suit in the U.S. District Court of the District of Columbia on behalf of four environmental groups. They argue the U.S. Bureau of Ocean Energy Management didn\'t fully assess the April 2010 oil spill in the Gulf of Mexico. SELC claims BOEM failed to adequately consider the spill and didn\'t incorporate \"new understandings\" of the risks posed by offshore drilling. Catherine Wannamaker, senior attorney for the SELC, said BOEM was moving forward in the gulf with the same mindset that led to the disaster in the first place. \"It\'s easier for the government and oil companies to return to business as usual without considering the oil spill\'s impacts on the gulf, but it\'s illegal and irresponsible,\" she said in a statement. U.S. regulators said last week BP was notified of five additional regulatory violations stemming from operations at the Macondo well, which failed and caused the oil spill. A U.S. government investigation into the accident concluded BP, Transocean and Halliburton committed a series of regulatory violations at the site. An October report listed seven violations for BP and four each for Transocean and Halliburton. A lease sale Wednesday has attracted more than 200 bids for blocks in the Gulf of Mexico that could collectively hold as much as 423 million barrels of oil and 2.6 trillion cubic feet of natural gas.