WASHINGTON/NEW YORK (Reuters) – Former US President Barack Obama and two members of his cabinet were among the targets of suspected package bombs delivered to high-profile Democrats and CNN in what New York officials on Wednesday branded an act of terrorism.

The suspicious parcels, at least five in all, were intercepted before any reached their intended recipients, who included former Secretary of State Hillary Clinton, former Attorney General Eric Holder and former CIA director John Brennan, the FBI said.

None of the packages detonated, and nobody was hurt. There was no immediate claim of responsibility.

But news of the threats heightened tensions in a nation deeply polarized ahead of elections on Nov. 6 that will decide whether Democrats take control of one or both houses of Congress from Republicans and deny President Donald Trump the majority his party now holds in both.

The first package, which turned up on Monday, was addressed to billionaire financier George Soros, a prominent Democratic Party donor and frequent target of right-wing conspiracy theories.

But the parcel intended for Holder ended up rerouted to the return address that had been printed on all five packages – the Florida office of U.S. Representative Debbie Wasserman Schultz, who formerly chaired the Democratic National Committee, according to the Federal Bureau of Investigation.

“It is possible that additional packages were mailed to other locations,” the FBI said in a statement on its website.

US Representative Maxine Waters, a veteran Democratic congresswoman from Los Angeles, said her Capitol Hill office was the target of a suspicious package that “has been referred to the FBI.”

The five other packages confirmed by the FBI in its statement were all described as similar in appearance, consisting of a manila envelope with a bubble-wrap interior containing “potentially destructive devices.”

Each bore a computer-printed address label and six “Forever” postage stamps, the FBI said.

Other officials said the devices contained in the envelopes were all similar to one found in the mailbox of the Soros home and later detonated by police.

The US Secret Service intercepted packages addressed to Obama at his Washington home and to Clinton at her home in New York state. The CNN bureau in New York also received a package, leading police to evacuate the Time Warner building in a busy Manhattan neighborhood near Central Park.

“So far the devices have been what appeared to be pipe bombs,” John Miller, the New York City police deputy commissioner for intelligence and counterterrorism, told a news conference.

“This clearly is an act of terror attempting to undermine our free press and leaders of this country through acts of violence,” New York Mayor Bill de Blasio told a news conference.