U.S. officials are planning to unveil charges Wednesday related to the theft of personal data that affected hundreds of millions of Yahoo users and disrupted the company’s sale to Verizon, according to people familiar with the matter.

At least some of the alleged hackers have ties to the Russian government, said the people, who added the national security division of the Justice Department and the Federal Bureau of Investigation plan to announce the charges Wednesday morning.

In September, Yahoo revealed hackers penetrated its network in late 2014 and stole personal data on more than 500 million users. The company concluded that it had been breached by “a state-sponsored actor.” The 2014 incident was separate from another much larger theft, affecting more than a billion accounts, that Yahoo disclosed in December and that dated back to 2013.

It is unclear if the charges are related to one or both of the breaches. The Russian Embassy in Washington didn’t immediately return a request for comment.

Earlier Tuesday, Bloomberg reported the Justice Department plans to accuse four people of participating in the security breaches, including one person in Canada and three people in Russia.

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