U.S. intelligence officials have told Congress that Guantanamo Bay detainees who were "recently" released are already trying to rejoin terrorist groups, according to a key Republican lawmaker.

"The committee has just received a troubling new report from the intelligence community indicating that former detainees recently transferred out of Guantanamo Bay by your administration are attempting to return to terrorism," House Foreign Affairs Committee chairman Ed Royce, R-Calif., wrote Tuesday in a letter to the White House. "Even more concerning, this report indicates that the country to which these detainees were transferred has little ability to prevent their return to the battlefield — a fact known to your Administration prior to their transfer."

The Defense Department transferred four detainees into Saudi Arabian custody on Jan. 5 and sent another detainee to Cabo Verde on Dec. 4. But it's not clear from the letter which transfers have ended up returning to terrorist groups. "Due to the classified nature of this intel, I don't have any details to provide beyond what is included in this letter," a committee spokesman said.

"In light of this dangerous revelation, I again ask that you immediately halt all transfers from Guantanamo Bay and take steps to secure former detainees who pose a threat to U.S. national security," Royce wrote.

Read more on WashingtonExaminer.com