WASHINGTON (Reuters) - The Republican head of the U.S. House of Representatives Intelligence Committee apologized on Thursday for the way he handled sensitive allegations about U.S. spy agency surveillance of President Donald Trump’s team.

Representative Devin Nunes was criticized by colleagues on Wednesday for calling a news conference to announce that the communications of members of the team that ran Trump’s transition to the presidency were swept up in incidental surveillance targeting foreigners.

Democrats were upset that Nunes made the comments to the media and then briefed Trump in the White House without informing them. They questioned whether the intelligence panel could run a credible investigation.

A Republican intelligence committee aide said on Thursday that Nunes had apologized to Democrats on the panel.

“Yes, he apologized to the minority on the committee today for going public and to the (White House) with his announcement yesterday before sharing the information with the minority. He pledged to work with them on this issue and share information with them about it,” the aide told Reuters.

The panel is conducting one of the main congressional investigations over allegations by U.S. intelligence agencies that Russia sought to influence the 2016 presidential election, including claims of ties between Trump’s team and Moscow. Russia denies the allegations.

Representative Jackie Speier, a Democrat on the panel, said Nunes had apologized “in a generic way.”

Asked if Nunes knew whether Trump’s associates were party to these communications or if they could have been communications between two foreigners talking about Trump’s associates, Nunes’ spokesman said:

“He (Nunes) said he’ll have to get all the documents he requested from the IC (intelligence community) about this before he knows for sure.”

House Permanent Select Committee on Intelligence Chairman Devin Nunes speaks to the media about President Trump's allegation that his campaign was the target of wiretaps. REUTERS/Aaron P. Bernstein

At a hearing of the committee on Monday, FBI director James Comey confirmed the existence of the investigation for the first time.

The top Democrat in the House, Nancy Pelosi, on Thursday described Nunes as “a willing stooge” of Trump who had “committed a stunt at the White House” with his comments.

“The necessity of an independent investigation is increasingly being recognized,” she said, referring to the probe involving Russia.

The White House had on Wednesday seized on Nunes’ remarks, which had cited anonymous sources, to bolster Trump’s unproven assertion on Twitter this month that President Barack Obama wiretapped his election campaign headquarters in Manhattan’s Trump Tower.

Nunes himself has said that the information he had did not support Trump’s allegation. He also said that none of the surveillance he knew about was related to Russia.

Democrats said Nunes may have revealed classified information with his comments to reporters but the congressman’s spokesman said that he did not.

Nunes, who was a member of Trump’s transition team, seemed contrite on Thursday for the timing and manner of his statement.

“There was a lot going on yesterday and it was a judgment call on my part. At the end of the day, sometimes you make the right decisions and sometimes you make the wrong ones but you’ve got to stick by the decisions you make,” he told reporters after the intelligence committee’s regular classified meeting.

Another Democrat on the committee, Representative Eric Swalwell, told MSNBC that its members had not yet seen the material referred to by Nunes.

The House committee is investigating whether Russia hacked emails of senior Democrats and released embarrassing information to hurt the campaign of Democratic candidate Hillary Clinton, interfering in the election to benefit Trump.