Egypt's former President Hosni Mubarak has been treated in a military hospital after slipping and injuring his head, state media say.Mubarak fell in a prison toilet last Friday, injuring his head and bruising his chest, Mena news agency reported.Deputy interior minister Gen Mohammed Ibrahim said Mubarak was returned to prison on Wednesday after an X-ray.Mubarak, 84, was given a life sentence in June for failing to stop the killing of protesters in last year's uprising.He was overthrown in February 2011 after weeks of mass unrest in which nearly 900 people died and more than 6,000 were injured.Mena, quoting security sources, said the former president had been moved to Maadi Military Hospital to receive treatment.Earlier this month, police in Spain said they had seized assets linked to the former leader worth some 28m euros (£23m; $34m).They took action after Egypt's new authorities made a request to block the assets of 130 people associated with his rule.An estimated 18.4m euros in financial products has been frozen in Spanish banks.