British politicians who examined the details of a drone strike which killed a British man in Syria said they were disappointed by the government's lack of transparency during investigations. On August 21, 2015, the UK conducted a drone strike in Raqqa for the first time outside the traditional theatre of war, killing 21-year-old British national Reyaad Khan, a suspected fighter with the Islamic State of Iraq and the Levant (ISIL, also known as ISIS), and two other people. "We are in no doubt that Reyaad Khan posed a very serious threat to the UK," the Intelligence and Security Committee in the UK said in a report on Wednesday. "There is nevertheless a question as to how the threat is quantified and in this instance whether the actions of Khan and his associates amounted to an'armed attack' against the UK or Iraq - which is clearly a subjective assessment," the committee said. "The [government's] failure to provide what we consider to be relevant documents is profoundly disappointing," the report added.

British lawmakers say a U.K. man killed by a Royal Air Force drone strike in Syria was an Islamic State group attack planner who posed a "very serious threat" to Britain. Parliament's Intelligence and Security Committee scrutinized the August 2015 strike that killed Reyaad Khan and two others. It was the first such drone strike acknowledged by the British government. Committee chairman Dominic Grieve said Wednesday that intelligence assessments left "no doubt that Reyaad Khan posed a very serious threat to the U.K." But he said lawmakers still had questions about ministers' decision-making, because some documents were withheld from the committee. Grieve said that was "profoundly disappointing."