President Trump lashed out at his predecessor on Twitter early Saturday, claiming former President Barack Obama ordered electronic surveillance at Trump Tower during the election campaign.

“Terrible! Just found out that Obama had my ‘wires tapped’ in Trump Tower just before the victory,” Trump tweeted at 6:35 a.m. as part of a flurry of early-morning tweets. “Nothing found. This is McCarthyism!”

The six-message tweetstorm intensified the controversy over his administration’s ties to Russia, fed by a torrent of leaks from opponents within the government.

An Obama spokesman denied the charges Saturday afternoon.

“Neither President Obama nor any White House official ever ordered surveillance on any US citizen,” said the spokesman, Kevin Lewis. “Any suggestion otherwise is simply false.”

Lewis’ statement did not address the possibility that Trump or his associates were surveilled as part of a Justice Department probe.

Trump, who drew a comparison to the Watergate scandal and called Obama a “bad (or sick) guy” in his tweets, did not offer evidence for his accusations.

The claims echo charges that had been espoused by conservative radio host Mark Levin on Thursday and were detailed Friday on Breitbart News.

The Justice Department and FBI requested court approval under the Foreign Intelligence Surveillance Act (FISA) to eavesdrop on Trump and his associates last June, according to published reports.

The FISA court, which typically accedes to administration requests, did not permit the monitoring.

Five months later, according to a timeline laid out by Breitbart, the FBI successfully filed a narrower FISA request to monitor a server within Trump Tower that was suspected of ongoing contacts with Russian banks.

No evidence of illicit communications was found in that probe, November news reports said.

Trump’s furious tone on Saturday was a departure from the generally warm statements he has made about Obama since taking office.

His diatribe began with a defense of Attorney General Jeff Sessions, who has been accused of lying under oath during his Senate confirmation hearings about his contacts with Russian Ambassador Sergey Kislyak.

“Just out: The same Russian Ambassador that met Jeff Sessions visited the Obama White House 22 times, and 4 times last year alone,” Trump later tweeted.

Sessions, who has denied wrongdoing, announced Thursday that he would recuse himself from any investigations into the 2016 presidential election, including probes into accusations of Russian meddling.

He will respond in writing on Monday to Senate Democrats’ questions about his testimony, the Justice Department said.

The White House did not respond to requests to elaborate on Trump’s Twitter accusations, which took his aides by surprise.

But backlash to the president’s assertions was swift.

“The Deflector-in-Chief is at it again,” tweeted House Minority Leader Nancy Pelosi. “An investigation by an independent commission is the only answer.”

At a South Carolina town hall, Republican Sen. Lindsey Graham, a frequent Trump critic, appeared to agree.

“It’s my job as a United States senator to get to the bottom of this,” he said, suggesting congressional investigations are likely to continue.

With Post Wire Services