Washington, Oct 25 (IANS): US President Donald Trump has called on people to be more civil in politics, after a series of suspected explosives were sent to high-profile US figures just weeks ahead of the mid-term polls.

None of the packages exploded. The Federal Bureau of Investigation has launched a hunt for their sender, the BBC reported.

Trump was speaking after parcels were sent to top Democrats, including former President Barack Obama and Hillary Clinton, besides New York Governor Andrew Cuomo, and media offices of CNN and the San Diego Union-Tribune, who are all prominent targets of right-wing criticism.

"Those engaged in political arena must stop treating political opponents as being morally defective," he said. "No one should carelessly compare political opponents to historic villains, which is done often," he added.

Speaking at a Wednesday night rally in Wisconsin, Trump vowed to catch the perpetrator and called on the media to "stop endless hostility". Critics called his latest remarks hypocritical, as he often uses vicious language against his opponents and the press.

However, he made no specific reference to the intended recipients of the packages, the BBC reported

Earlier CNN worldwide President Jeff Zucker criticised Trump and the White House Press Secretary Sarah Sanders for not understanding that "words matter". "There is a total and complete lack of understanding at the White House about the seriousness of their continued attacks on the media," Zucker said.

Suspected bombs were sent to locations in New York, the Washington DC area and Florida, authorities said on Wednesday. All the apparent targets were regularly criticised by conservatives -- especially by President Trump.

US authorities are investigating this as a connected series, officials said.

Sources told CNN that a suspicious package intended for California Democratic Maxine Waters was intercepted at a congressional mail screening facility in Maryland; New York Governor Andrew Cuomo received what he said was a device at his Manhattan office; and the San Diego Union-Tribune evacuated its building after "suspicious looking packages" were spotted outside.

CNN's New York bureau in the Time Warner Center was evacuated after a package containing a bomb, addressed to former CIA Director John Brennan, was discovered, city and local law enforcement officials said.

Later Wednesday night, two law enforcement sources told CNN that law enforcement officials were trying to track down a package addressed to former Vice President Joe Biden considered suspicious because of similarities to other packages.

The package was misaddressed and returned to sender.

The developments, which unfolded rapidly and continued steadily into the afternoon, touched off fear and confusion and immediately invited questions about the motives of those responsible.

Some Democrats have accused the president of inciting violence with his past rhetoric, while some of his supporters have said they believe the packages are part of a Democratic plot to win votes in the mid-term elections.

There is no evidence for this and the police have not released any information about any suspects. The attempted attacks come just under two weeks before the mid-terms, with US politics highly polarised.