Former Attorney General Eric Holder Eric Himpton HolderThe Hill's Campaign Report: Biden on Trump: 'He'll leave' l GOP laywers brush off Trump's election remarks l Obama's endorsements Obama endorses Warnock in crowded Georgia Senate race The Hill's Campaign Report: Trump's rally risk | Biden ramps up legal team | Biden hits Trump over climate policy MORE urged career employees of the FBI and Justice Department to "be prepared, be strong" in the face of unfair accusations in an ominous late-night tweet.

"To the career men & women at DOJ/FBI: your actions and integrity will be unfairly questioned. Be prepared, be strong. Duty. Honor. Country," Holder, an Obama administration attorney general, tweeted early Friday morning.

To the career men & women at DOJ/FBI: your actions and integrity will be unfairly questioned. Be prepared, be strong. Duty. Honor. Country. — Eric Holder (@EricHolder) June 30, 2017

ADVERTISEMENT

Holder's warning comes as the FBI continues investigating Russian interference in the presidential election, as well as possible links between President Trump's campaign and Moscow. Special counsel Robert Mueller is also probing Kremlin election meddling.

Trump has been critical of the investigations, calling them a "witch hunt" and ripping the agencies conducting them.

Holder made a similarly ominous statement the night that FBI Director James Comey was fired in May, tweeting: "To the career men and women at DOJ/FBI: you know what the job entails and how to do it. Be strong and unafraid. Duty. Honor. Country."