Trump calls for unity, asks media to be responsible after suspicious packages sent to Democrats

US President Donald Trump has called for unity against the "threat of political violence" after suspicious packages were sent to his predecessor Barack Obama, Hillary Clinton and CNN and asked the media to take the responsibility for setting a civil tone by stopping the "endless hostility" and "constant negative stories".

Trump's remarks came after a series of explosive devices discovered throughout the day on Wednesday.

The devices, which included pipe bombs, were sent to prominent Democrats and across the country and to CNN's New York office.

Obama and Clinton, who was Trump's opponent in the 2016 presidential election, received threats. Packages were also sent to Representative Debbie Wasserman Schultz, liberal philanthropist George Soros and California Democratic Congresswoman Maxine Waters.

The president condemned the explosive devices sent to these leaders, declaring that such threats are "an attack on our democracy itself."