NAIROBI — POLICE Tuesday charged a civil servant with the 1990 murder of Kenya's foreign minister, but two close aides of President Daniel arap Moi mentioned in connection with the slaying were set free.Jonah Anguka, a district commissioner from Kenya's Rift Valley area, was charged in a magistrate's court in Nairobi with the Feb. 14, 1990, murder of Foreign Minister Robert Ouko. But Police Commissioner Philip Kilonzo said in a statement that he had released former Industry Minister Nicholas Biwott and Hezekiah Oyugi, internal security chief at the time of Ouko's death, due to lack of evidence. Mr. Biwott and Mr. Oyugi were arrested two weeks ago after being named as prime suspects by former Scotland Yard detective John Troon at a judicial inquiry held in Ouko's western home town of Kisumu. Mr. Troon led a British team of detectives to investigate Ouko's death at Mr. Moi's request, but on delivery of his report Moi called for a court inquiry that lasted for 246 days. Moi fired Biwott and Oyugi after Troon testified in court, and then called an end to the inquiry before arresting the two men. Mr. Kilonzo's statement said that despite further investigation "in my opinion what has emerged falls, for the moment, short of what is required in law to support and justify a criminal charge." Oyugi's bodyguard, who also had been arrested two weeks ago, was released as well. Six others who were arrested last month were released last week.