US President Donald Trump  on Wednesday called for unity after suspected explosive devices were mailed to leading Democrats, including former president Barack Obama, saying acts of political violence have “no place” in the United States.

Trump’s comments at a White House event on opioid addiction were his first substantive reaction to the rash of bomb alerts, which also targeted his former Democratic rival for the presidency, Hillary Clinton.

“I want to say, at these times we have to unify and send one very clear and strong message that acts of political violence of any kind have no place in the United States of America,” he stated.