Pakistan's former military ruler Pervez Musharraf failed to appear on Tuesday before an anti-terrorism court due to "security reasons" for his trial in the assassination case of former premier Benazir Bhutto, prompting the judge to adjourn the hearing till August 20. Musharraf, who had been summoned to face charges of criminal conspiracy and the murder of Bhutto, was not brought to the Rawalpindi court due to threats to his life.If convicted, 69-year-old Musharraf can be sentenced to death or life imprisonment.Police told Judge Chaudhry Habibur Rehman that it was not safe enough to bring Musharraf to the court due to threats against his life.Judge Rehman adjourned the indictment until August 20 and ordered Musharraf to appear then.Bhutto was assassinated soon after an election rally in Rawalpindi in December 2007.Musharraf, the then president, blamed her killing on Pakistani Taliban chief Baitullah Mehsud, who denied any involvement. Mehsud was killed in a US drone attack in 2009.Musharraf has been kept in his house under arrest since April due to threats from Taliban. He returned to Pakistan in March after living in self imposed exile for about five years to contest the general elections in May. However, he was barred by Pakistani courts from contesting.He is also wanted in the death case of Balochistan rebel leader Nawab Akbar Bugti in 2006 and taking unconstitutional steps by imposing emergency and removing judges in 2007.