On 29 April 1992 a 25-year-old Captain Valentine Strasser led seven junior officers in the Sierra Leone army that included Lieutenant Sahr Sandy Lieutenant Solomon Musa Lieutenant Tom Nyuma Captain Julius Maada Bio and Captain Komba Mondeh that launched a military coup which sent president Momoh into exile in Guinea and the young soldiers established the National Provisional Ruling Council ( NPRC ) with Strasser as its chairman and Head of State of the country .