Defense Department officials had announced a security review following the attack, halting operational training for Saudi Arabian military students in the United States, though classroom instruction would continue.

US authorities have examined the identities, past activities and social media history of some 850 Saudis currently training on military bases in the US, said Garry Reid, the Pentagon's director for defense intelligence.

"We can report that no information indicating an immediate threat scenario was discovered," he said.

The checks come after Mohammed Alshamrani, a 21-year-old lieutenant in the Saudi Royal Air Force, opened fire in a classroom at Pensacola Naval Air Station in Florida on December 6, killing three American sailors and wounding eight other people before being shot dead by police.

Alshamrani, who was armed with a lawfully purchased Glock 9mm handgun, is reported to have posted a manifesto on Twitter before the shooting denouncing America as "a nation of evil."

The Pentagon reviewed policies for screening foreign students but the suspension of operational training only applied to Saudi students, officials said at the time.

Operational training for Saudi students can theoretically resume, but operations are expected to be much lighter during the holiday season, a senior Pentagon official said Thursday on condition of anonymity.

Some 5,000 international military personnel are undergoing training in the US, including 850 Saudis among all branches.

There are 300 Saudis in the Navy alone.