Data breaches at the U.S. government's personnel management agency by hackers involves millions more people than previously estimated, U.S. officials said on Thursday. The Office of Personnel Management (OPM) said data stolen from its computer networks included Social Security numbers and other sensitive information on 21.5 million people who have undergone background checks for security clearances.

OPM said the stolen personal identification data included: Social Security numbers; residency and educational history; employment history; information about immediate family and other personal and business acquaintances; and health, criminal and financial history. Also stolen were about 1.1 million fingerprints, the agency said.

OPM said it is highly likely that anyone who went through a background investigation after 2000 was affected by the cyber breach. Those who underwent background checks before 2000 might be impacted but it is less likely, the personnel agency said.

That is in addition to data on about 4.2 million current and former federal workers that was stolen in what the OPM called a "separate but related" hacking incident. Because many people were affected by both hacks, a total of 22.1 million people were affected.

Those exposed included 19.7 million who applied for the clearances - current, former, and prospective federal employees and contractors - plus 1.8 million non-applicants, mostly spouses or co-habitants of applicants, the agency said.

Lawmakers from both parties demanded OPM Director Katherine Archuleta's removal. But The White House said Obama retains confidence in Archuleta.

The United States has identified China as a suspect in the massive hacking of the U.S. government agency, an assertion China's Foreign Ministry dismissed as "absurd logic."