Several mail carriers were left with minor injuries after the assaults in Maryland and Washington, D.C.

A team of divers found Maeve Kennedy Townsend McKean's body four kilometres away from her mother's home.

The 27-year-old has been in custody in the U.S. since he and two of his American cohorts were arrested a month ago by the FBI.

The National Weather Service was using radar data and making damage assessments to confirm many reports of tornadoes touching down, including spots in Virginia and Maryland.

The identity of the person killed was withheld pending notification of family members, Maryland State Police said in a news release.

Anthony Oluseye Akinyemi, 56, had been charged with sexual abuse of a minor and was convicted last week in Baltimore City Circuit Court.

A poll, conducted by the Pew Research Center, found most Americans believe the tone and nature of political debate in the United States under Trump has worsened.

The victim was taken to hospital after the assault with what are believed to be non-life-threatening injuries.

He died early Thursday of complications from longstanding health issues, his office said.

In a weeklong series of attacks, Trump called the Baltimore district a "rat and rodent infested mess" and complained about Cummings, whose district includes key parts of the city.