The Pentagon has completed re-screening all Saudi students in U.S. military training programs following a deadly Dec. 6 shooting rampage at Naval Air Station Pensacola, Defense Department officials announced Thursday.

No indications of additional threats have surfaced, they said.

Moving forward, DoD plans to increase vetting practices for Saudi Arabian and other foreign nationals in training at military bases in the U.S., including checks of their social media posts.

The recent screenings included about a dozen friends of 21-year-old Saudi Royal Air Force 2nd Lt. Mohammed Saeed Alshamrani, who was shot to death by a sheriff's deputy after killing three and injuring eight others in a classroom building at NAS Pensacola.

In a statement read in a conference call with reporters, Garry Reid, the director for Defense Intelligence, said the department ran all of the approximately 850 Saudi students currently in military training in the U.S. through databases and found "no information indicating an immediate threat scenario."

Related: Hundreds Attend Military Funeral for Sailor Slain in Pensacola Attack

However, a senior defense official, speaking on background, cautioned that a threat may still exist that was not turned up in the check.

Alshamrani and all other Saudi students had already undergone rigorous background checks by the Defense, State and Homeland Security Department before being admitted into U.S. training, a senior defense official said last week. But Alshamrani's troublesome social media activities may have gone unnoticed.

A Twitter account in Alshamrani's names included anti-American statements before the shootings, and a Saudi intelligence report obtained by the Washington Post showed that he may have been influenced by at least four radical clerics.

In the Thursday call with reporters, a senior defense official said that future screenings will include social media checks before Saudi and other foreign national students are permitted access to U.S. bases.

More than one million foreign students have gone through U.S. military training programs since 2000, and there had not been a so-called "insider threat" attack until the Pensacola shootings, a senior defense official said.

The approximately 150 Saudi students at Pensacola have been grounded for operational training since the shootings, but are continuing classroom instruction, according to defense officials. In addition, Alshamrani's acquaintances have been restricted to quarters and are being monitored by the FBI.

In addition to expanded database checks, the enhanced vetting for all foreign nationals in military training in the U.S. could include efforts by the service branches to conduct random searches, more identity checks at entry gates and "continuous evaluations throughout the training cycle," the senior defense official said.

Similar checks were run on all of the more than 5,000 foreign students of all nationalities currently in training at military bases. Those checks also failed to turn up threat indicators, defense officials said.

The initial vettings ordered up last week by Defense Secretary Mark Exper were part of "the most significant reform of the background investigation process in decades, adopting new technologies and improving our awareness of personnel security threats," Reid said.

-- Richard Sisk can be reached at Richard.Sisk@Military.com.

Read More: It's Official: The Air Force's Huey Replacement is Named 'Grey Wolf'