GENEVA - Medecins Sans Frontieres called on Thursday for an independent investigation into air strikes that killed 25 people at an MSF-sponsored hospital in north Syria, saying there was a probability that they were carried out by the government-led coalition.Dr. Joanne Liu, international president of the medical charity known as Doctors Without Borders, said that accounts from surviving staff at the hospital in the province of Idlib led it to believe that Syrian and Russian forces were involved."We say probability because we don't have more facts than the accounts from our staff," Liu told a news briefing. "The only thing predominantly in the region is the Syrian government-led coalition."MSF said it had not provided the hospital's GPS coordinates to Syrian or Russian authorities, at the request of the staff.