WASHINGTON (Reuters) - The Saudi ambassador to the United States visited a U.S. naval air station in Florida on Thursday to extend her condolences for a shooting attack by a Saudi Air Force officer that killed three people last week, the Saudi embassy said.

The attack brought fresh complications to U.S.-Saudi relations and prompted the Pentagon to halt operational training for some 850 visiting Saudi Arabian military personnel until further notice as part of a “safety standdown.”

The Saudi ambassador, Princess Reema bint Bandar Al Saud, met with members of the Pensacola Naval Air Station command “and reiterated her condemnation for this horrific attack,” the Saudi embassy said.

She pledged to provide “any assistance possible to accelerate the investigation.”

The FBI has said U.S. investigators believe Saudi Air Force Second Lieutenant Mohammed Saeed Alshamrani, 21, acted alone when he opened fire at the base on Friday, leaving three people dead and eight injured.

Alshamrani was fatally shot by a deputy sheriff.

Still, around a dozen Saudi military personnel who knew Alshamrani are being confined to the base and are cooperating with the investigation, the Pentagon said on Thursday.

The Pentagon said the Saudi military personnel “have access to classroom instruction, food, medical staff, a U.S. military imam, and their commanding officer.”