US Accidentally Killed American al-Qaeda Hostage Warren Weinstein died in January drone strike By Kate Seamons, Newser Staff Posted Apr 23, 2015 8:59 AM CDT 31 comments Comments This image made from video released anonymously to reporters in Pakistan on Dec. 26, 2013, shows Warren Weinstein. (AP Photo via AP video) (Newser) – "I profoundly regret what happened," President Obama today said in reference to a January drone strike that accidentally killed two al-Qaeda hostages. The Wall Street Journal reports the deaths of American development expert Dr. Warren Weinstein and Italian aid worker Giovanni Lo Porto mark the first time the US has inadvertently killed a hostage in a drone strike. Obama said he takes "full responsibility" for the operation, which he framed as a mission "fully consistent" with established guidelines, the AP reports. An independent review of the incident is underway, and a statement from the White House press secretary states "we had no reason to believe either hostage was present." The Journal reports that in the hundreds of hours of surveillance the CIA amassed on the al-Qaeda-linked compound in the Afghanistan-Pakistan border region, there was zero indication the hostages were present. Weinstein had been held since he was taken from his guarded Lahore home in August 2011; Lo Porto was a captive since 2012, and, per the statement, "many within our government spent years attempting to locate and free" them. The Journal reports the US was unaware the men were being held together prior to the strike. The statement adds two other Americans who were working with al-Qaeda were also inadvertently killed in January: Ahmed Farouq likely died in the strike on the aforementioned compound; Adam Gadahn, a spokesman for the terrorists, is thought to have died in a separate strike.