An Islamist militant jailed for plotting al-Qaida bombings since his release from prison in 2012 after serving time for his role in the assassination of Anwar Sadat, has died in hospital, security sources said on Friday.Nabil al-Maghraby, a former naval intelligence officer, was taken to hospital from prison 10 days ago after his health deteriorated significantly, the sources said."He suffered from cancer, liver illness and old age," said one source, who estimated his age at about 76. Egyptian newspaper reports carried news of Maghraby's death on Friday.Maghraby had been released from jail in 2012 after serving 31 years for taking part in the 1981 assassination of Sadat. The Egyptian president was killed by Islamist members of the military opposed to his 1979 peace treaty with Israel.Maghraby was arrested again in late 2013 for being "part of a terror organization and for planning bomb attacks in the country", a security source said at the time of his arrest.He was among a group of defendants being tried over accusations that include killing policemen, attacking a church and joining a terrorist organization, the sources said.Nabil's nephew Ahmed al-Maghraby said the prison had informed the family about Maghraby's death. "They went there after Friday prayers, received the body and buried him in their cemetery in Giza," he told Reuters.