By ZEKE MILLER, ERIC TUCKER and WILL WEISSERT

WASHINGTON (AP) — The Trump administration has fired more than a dozen independent inspectors general at government agencies, a sweeping action to remove oversight of his new administration that some members of Congress are suggesting violated federal oversight laws.

The dismissals began Friday night and were effective immediately, according to a person familiar with the actions who spoke on condition of anonymity to provide details that have not been made public. The firings were carried out without giving Congress 30-day notices of removal of inspectors general –- something that even a top Republican said violated the law.

“There may be good reason the IGs were fired. We need to know that if so,” Sen. Chuck Grassley, chair of the Senate Judiciary Committee, said in a statement. “I’d like further explanation from President Trump. Regardless, the 30-day detailed notice of removal that the law demands was not provided to Congress,” said Grassley, R-Iowa.

President Donald Trump was . The White House press office did not respond to requests for comment.

in Las Vegas on Saturday for a speech

The role of the modern-day inspector general dates to post-Watergate Washington, when Congress installed offices inside agencies as an independent check against mismanagement and abuse of power. Though inspectors general are presidential appointees, some serve presidents of both parties. All are expected to be nonpartisan.

“Yesterday, in the dark of night, President Trump fired at least 12 independent inspector generals at important federal agencies across the administration,” Senate Democratic leader Chuck Schumer of New York said Saturday on the chamber’s floor. “This is a chilling purge and it’s a preview of the lawless approach Donald Trump and his administration are taking far too often as he’s becoming president.”

Schumer said the dismissals are “possibly in violation of federal law” and help demonstrate that the move “is a glaring sign that it’s a golden age for abuse in government and even corruption.”