Japanese police are investigating phone calls threatening to kill U.S. Ambassador Caroline Kennedy and Alfred Magleby, the U.S. consul general, an unnamed local police official told The Associated Press.
{mosads}Local media reports indicated the death threats came from an English-speaking person on phone calls to the U.S. Embassy in Tokyo last month, according to CBS News.
The reports came as first lady Michelle Obama was expected to arrive in Tokyo for a three-day visit.
Earlier this month U.S. Ambassador to South Korea Mark Lippert was injured in a knife attack by an anti-American activist and was released from the hospital after several days.
A request for comment from the State Department was not immediately returned.
Kennedy, the daughter of former President John F. Kennedy, was appointed ambassador to Japan by President Obama in 2013.