NAIROBI, Kenya ��" The EU Naval Force freed six Somalis seized after their companion was shot dead by a private security contractor during an attempt to hijack a ship off the East African coast, a naval spokesman said on Thursday. The navy let the six go after the captain of the MV Almezaan said he could not identify the men detained by the Spanish navy as the group of pirates who attacked him, said Cmdr. John Harbour. One of the suspected pirates died after men aboard the Almezaan opened fire while waiting for help from a warship. When the warship arrived, it detained the six surviving men and the body of the seventh. Legal experts say the incident illustrates the lack of regulation for a growing army of private security contractors working onboard ships in the high seas. There have been a number of new companies setting up in the lucrative maritime private security business. Maritime officials worry that a proliferation of weapons could escalate the level of violence used in attacks, potentially endangering crews. They also warn that laws governing the use and carriage of weapons are unclear and could open a ship owner to potential lawsuits in the case of a fatality.