Police in Berlin detonated a suspicious package sent to German President Joachim Gauck on Friday (April 19), according to a presidential spokesman.

"A controlled explosion was carried out in the park next to the presidential palace Bellevue. An initial assessment showed it posed a concrete danger," the spokesman said by telephone.

The incident came a day after U.S. authorities charged a man with mailing letters to President Barack Obama and a U.S. senator containing a substance that preliminarily tested positive for ricin, a highly lethal poison made from castor beans.

Presented by Adam Justice