WASHINGTON - President Donald Trump's administration targeted bank regulators, rocket scientists and tax enforcers on Tuesday as it sought to fire thousands more federal employees in an unprecedented assault on the U.S. civil service.

With tax-filing season underway, senior officials at the Internal Revenue Service identified 7,500 employees for dismissal, with possibly more on the chopping block, according to a person familiar with the matter.

Tech billionaire Elon Musk's Department of Government Efficiency, or DOGE, has swept through federal agencies slashing thousands of jobs since President Donald Trump became president last month and put Musk in charge of a drastic overhaul of government.

The White House has not said how many people it plans to fire and has given no numbers on the mass layoffs so far. The information to date has come from employees of federal agencies.

The Federal Deposit Insurance Corporation, which oversees banks, said it has fired an unknown number of new hires, according to an email seen by Reuters. The cuts could potentially worsen staffing problems at a 6,000-person agency where more than one in three workers are eligible for retirement.

Roughly 1,000 new hires, including rocket scientists, at NASA were expected to be laid off on Tuesday as well, according to two people familiar with the U.S. space agency's plans, with more cuts possible.

"People are scared and not speaking up to voice dissent or disagreement," said one employee at the 18,000-person agency who spoke on condition of anonymity.

Layoffs were also expected at the Federal Emergency Management Agency, which handles flood insurance and disaster response, as well as its parent agency, the Department of Homeland Security, sources said.

The Trump administration plans to fire hundreds of senior Department of Homeland Security employees this week, according to an administration official and a second source familiar with the matter. The planned firings, first reported by NBC News, would target people viewed as not aligned with Trump, the sources said.

Among the workers swept up in the overhaul of dozens of agencies are those reviewing Musk's brain implant company Neuralink and others monitoring an outbreak of H5N1 bird flu that has infected millions of chickens and cattle this year.

Musk's team has said it has saved $55 billion so far, a relatively small slice of the annual $6.7 trillion federal budget. The DOGE website has begun giving more details of government contracts it has canceled after widespread complaints that its work was not transparent.

The cost-cutting drive has focused largely on probationary employees hired within the past year who lack full employment protections.

At the IRS, that includes 7,500 involved in tax enforcement and compliance, but not those deemed essential for the April tax filing season, according to a person familiar with the matter. The tax-collecting agency could be asked to trim its 100,000-strong workforce further, the source said.

Republicans had objected to an IRS staff expansion undertaken by Democratic President Joe Biden that independent budget analysts said would boost tax collections and help close the persistent U.S. budget gap.

RESIGNING IN PROTEST

The overhaul comes as Trump attempts to exert even tighter control over the Justice Department, an agency traditionally seen as independent of White House influence.

Several department officials resigned last week after refusing a directive from a Trump appointee to drop a corruption case against New York Mayor Eric Adams. Another top prosecutor, Denise Cheung, resigned on Tuesday after refusing to investigate a government contract awarded during Biden's tenure.

The acting head of the Social Security Administration, Michelle King, resigned over the weekend after Musk's team asked for access to a vast database of personal and financial data at the agency, which handles retirement and other safety-net programs, according to a person familiar with the matter.

With opposition Democrats out of power in Congress, opponents have relied on the courts to stop the downsizing effort, with mixed success so far.

A federal judge in Washington on Tuesday declined to prevent Musk's team from accessing student-loan records at the Department of Education, saying a student group had failed to show they would misuse sensitive financial information.

Another judge is expected to rule on Tuesday on a request by Democratic attorneys general from 13 states to block Musk's personnel from reviewing sensitive records at several other agencies.