WASHINGTON – Two U.S. attorneys are taking over separate FBI investigations into leaks of national security information that critics have accused the White House of orchestrating to improve President Obama’s re-election chances, a claim Obama calls “offensive” and “wrong.”

Recent news articles contained details of U.S. involvement in a partially successful computer virus attack on Iran’s nuclear program and on the selection of targets for counterterrorism assassination plots. The leaked information generally painted Obama as a decisive and hands-on commander in chief.

“The notion that my White House would purposely release classified national security information is offensive. It’s wrong,” Obama said at a news conference Friday. “And people I think need to have a better sense of how I approach this office and how the people around me here approach this office.”

Obama promised investigations into the source of leaks about U.S. involvement in cyberattacks on Iran and drone strikes on suspected terrorists.

“We’re dealing with issues that can touch on the safety and security of the American people, our families or our military personnel or our allies, and so we don’t play with that,” he said.

Hours later, Attorney General Eric Holder announced that two U.S. attorneys will lead a pair of criminal investigations already under way into possible unauthorized disclosures of classified information within the executive and legislative branches of government.

Holder said he was confident the prosecutors would follow the facts and evidence wherever they led.

“The unauthorized disclosure of classified information can compromise the security of this country and all Americans, and it will not be tolerated,” he said.

Holder assigned Ronald Machen, the U.S. attorney for the District of Columbia, and Rod Rosenstein, the U.S. attorney for the District of Maryland, to direct separate probes that are already being conducted by the FBI.

Three weeks ago, FBI Director Robert Mueller said the bureau had launched an investigation into who leaked information about an al-Qaida plot to place an explosive device aboard a U.S.-bound airline flight. Separately, calls from Capitol Hill have mounted urging a leak probe into a New York Times story a week ago about U.S. involvement in cyberattacks on Iran.

Obama said his administration has “zero tolerance” for such leaks and that there would be an internal administration probe.

“We have mechanisms in place where if we can root out folks who have leaked, they will suffer consequences,” the president said. “In some cases, it’s criminal. These are criminal acts when they release information like this. And we will conduct thorough investigations, as we have in the past.”

Leaders of the Senate and House intelligence committees said Thursday they were drafting legislation to further limit access to highly classified information and possibly impose new penalties for revealing it. The chairman of the House Intelligence Committee said he will investigate recent leaks.