FBI investigating reports of JPMorgan Chase breach

LOS ANGELES (KABC) -- Federal agents are investigating a potential major breach of JP Morgan Chase's computers and those of at least one other major financial institution, law enforcement sources tell ABC News.

Investigators are trying to determine whether sensitive customer account information was compromised.

"We are working with the United States Secret Service to determine the scope of recently reported cyber-attacks against several American financial institutions," the FBI said in a statement.

JPMorgan Chase says it has not seen unusual levels of fraud activity, but customers were urged to contact the bank if they think they may be a victim.

The bank says it is working closely with law enforcement officials and taking additional steps to keep confidential information safe.

Investigators are looking into reports that the possible breach originated in Russia. According to Bloomberg, Russian hackers reportedly attacked the U.S financial system earlier this month in possible retaliation against U.S. government-sponsored sanctions aimed at Russia.

ABC News and the Associated Press contributed to this report.