No one was injured by the package bomb, authorities said.
Yet the New York Police Department has warned all banks in the city to beef up mailroom security in light of the episode. The package in Germany was made of explosives and shrapnel, and it was discovered in the mailroom at Deutsche Bank's headquarters. The package was detected by X-ray technology, police said. It did not detonate.
Today Deutsche Bank received a suspicious package addressed to Mr. Ackermann in Frankfurt. The relevant unit of the bank informed the police, who have started an investigation, Deutsche Bank told Fox News.
Ackermann has played a role in the effort to solve Europe's financial crisis as an advisor to German Chancellor Angela Merkel, possibly a reason he was targeted. Sources said the device was rudimentary in composition.
U.S. officials have said there are no strong leads in the case.
As of right now, the FBI is aware of the situation and we're looking into it, said Kelly Langmesser, a spokeswoman for the Federal Bureau of Investigation, in an interview with BusinessWeek.
Ackermann, and other Deutsche Bank executives, are also being investigated over alleged false testimony they gave during a major civil lawsuit in Germany, raising more questions about the origins of the package.
Deutsche Bank opened a branch in New York in 1979.