President Obama has apologised after two Western hostages were inadvertently killed in a US attack on an al Qaeda base in January.<br /><br /> Warren Weinstein, an American doctor, and Italian Giovanni Lo Porto had been held in the border region of Afghanistan and Pakistan. <br /><br /> The US government has said the operation involved drone strikes.<br /><br /> Obama said US forces believed the target was an al Qaeda compound with no civilians present.<br /><br /> “This morning I has expressed my grief and condolences to the families of two hostages – one American, Warren Weinstein, and an Italian, Giovanni Lo Porto – who were tragically killed in a US counter-terrorism operation. Warren and Giovanni were aid workers in Pakistan devoted to improving the lives of the Pakistani people,” the president said at a White House briefing.<br /><br /> Weinstein, was was 73, was abducted in Lahore in 2011 while working for a US consulting firm. Lo Porto had been missing in Pakistan since January 2012.<br /><br /> The American had been seen in videos rel
