Democrat presidential candidate Hillary Clinton has said Americans must choose "resolve not fear" in response to terror threats as she accused rival Donald Trump of inadvertently aiding Isis recruitment efforts.
Mrs Clinton said Mr Trump's "irresponsible reckless rhetoric" was "not grounded in fact" and cited a former head of US counter terrorism's claim that the "the kind of rhetoric and language that Mr Trump has used is giving aid and comfort to our adversaries".
The former New York senator addressed security measures in the wake of the weekend bombing in New York, which left 29 people injured.
Mrs Clinton's response included a pitch for the presidency, emphasising the public support she has received from security officials from both major parties and her experience as US secretary of state.
"I'm the only candidate in this race that has been part of the hard decisions to take terrorists off the battlefield," she said.
Mrs Clinton called for a coalition air strikes against Isis strongholds to be increased while the US launches an "intelligence surge" at home to try to detect and stop attacks before they are carried out.
She also urged a greater role for Silicon Valley in aiding the US government in tracking terrorists online and countering Isis recruitment and called for measures to build up trust between Muslims and police.
"This threat is real but so is our resolve," she said. "Let us be vigilant but not afraid. We have faced threats before."
Authorities are investigating whether Ahmad Rahami, who was not on US counter-terrorism lists, acted alone or as part of a terror cell.
Investigators studying CCTV footage may have identified the same man at each location, law enforcement sources reported to have said.
At least 29 people have been injured in an explosion which rocked Manhattan. Here's what we know so far.