A TOP aide to Abu Musab al-Zarqawi, head of the al-Qaeda operation in Iraq and accused of masterminding high-profile suicide bombings in the country, has been killed by Iraqi security forces, defence officials have confirmed. -SNIP-Abu Zubair, also known as Mohammed Salah Sultan, was shot dead in the northern city of Mosul on Friday, when he was caught in an ambush set up by Iraqi security forces, the officials said, confirming a report by Mosul police. No other details of the operation were provided. But officials said Abu Zubair was wearing a suicide belt filled with metal pellets when he...