Officials in the United States have not been able to verify Israeli claims that the Shin Bet intelligence agency foiled an "advanced" Al-Qaida plot to bomb the U.S. Embassy in Tel Aviv and other targets, NBC News reported Wednesday.

Shin Bet officials announced on Wednesday that they had arrested three Palestinians in December, two of them East Jerusalem residents with Israeli identification cards, for alleged involvement in an Al-Qaida plan to carry out the attacks. Details of the arrest were revealed after a gag order on the case was lifted.

The group had planned two simultaneous suicide attacks, the Shin Bet said, one at the U.S. mission in Tel Aviv and the other at the International Convention Center in Jerusalem.

The Israeli officials claimed the suspects had been recruited over the Internet by an operative working for Ayman al-Zawahiri, who replaced Osama bin Laden as the terror group's leader after U.S. forces killed him in May 2011.

However, several U.S. officials told NBC News they were unable to verify the Shin Bet's claims, including the alleged link to Al-Qaida.

"The validity is something we're still looking at," a senior State Department official, speaking on condition of anonymity, told NBC News.

State Department spokeswoman Marie Harf on Wednesday also said U.S. investigators and intelligence officials were not yet able to corroborate the Israeli information and declined comment on specifics of the case.

"Obviously we're looking into it as well," Harf told reporters in Washington on Wednesday. "I don't have reason to believe it's not true. I just don't have independent verification."

She said there were no plans to evacuate the U.S. Embassy in Tel Aviv and was not immediately aware of stepped-up security measures there in light of the arrests.