Trump, the Republican nominee, had just arrived in Colorado Springs, Colorado, for a rally Saturday night when he said 'a bomb' had gone off in New York.
He was filmed saying at the event: 'I must tell you that just before I got off the plane, a bomb went off in New York and nobody knows exactly what's going on.
'But boy, we are living in a time - we better get very tough folks, we better get very, very tough.
'Just happened, so we'll find out, but it's a terrible thing that's going on in our world and in our country and we are going to get tough and smart and vigilant and we're gonna end it. We're gonna end it.'
Clinton, the Democratic nominee, said she has been briefed about explosions in New York and New Jersey and a mall attack in Minnesota and is calling on the nation to support first responders and to pray for victims.
She told reporters traveling with her: 'I've been briefed about the bombings in New York and New Jersey, the attack in Minnesota. Obviously we need to do everything we can to support our first responders - also, to pray for the victims.
'We have to let this investigation unfold. We've been in touch with various officials including the mayor's office in New York to learn what they are discovering as they conduct this investigation.
'And I'll have more to say about when we actually know some facts.'