The U.S. on Monday canceled training schemes for 21 Saudi Arabian air cadets and sent them packing back to their home country, following a probe into a deadly shooting at a U.S. naval base last month.

Attorney General William Barr told reporters that the trainee pilots were heading home on the conclusion of an investigation into Saudi national Mohammed Alshamrani, a military aviation student who went on a killing spree in Pensacola, Florida, in December.

“While there was no evidence of assistance or pre-knowledge of the attack by other members of the Saudi military, or any other foreign

Read more: US expels 21 Saudi cadets after Florida shooting probe