LONDON (AP) — 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."

In January, Attorney General Jeremy Wright said it is legal to kill militants overseas if they pose an immediate or unstoppable threat.