Chambliss, the top Republican on the Senate Intelligence Committee, said it was that chatter that prompted the Obama administration to order the Sunday closure of 22 embassies and consulates and issue the travel warning.
Rep. C.A. Dutch Ruppersberger of Maryland, the top Democrat on the House Intelligence Committee, told ABC's "This Week" that the threat intercepted from "high-level people in al-Qaida in the Arabian Peninsula" was about a "major attack."
Yemen is home to al-Qaida's most dangerous affiliate, blamed for several notable terrorist plots on the United States. They include the foiled Christmas Day 2009 effort to bomb an airliner over Detroit and the explosives-laden parcels intercepted the following year aboard cargo flights.
Rep. Peter King, the New York Republican who leads the House Homeland Security subcommittee on counterterrorism and intelligence, told ABC that the threat "was specific as to how enormous it was going to be and also that certain dates were given."
The Obama administration's decision to close the embassies and the lawmakers' general discussion about the threats and the related intelligence discoveries come at a sensitive time as the government tries to defend recently disclosed surveillance programs that have stirred deep privacy concerns and raised the potential of the first serious retrenchment in terrorism-fighting efforts since Sept. 11.
Senate Judiciary Committee Chairman Patrick Leahy, D-Vt., has scoffed at the assertion by the head of the National Security Agency that government methods used to collect telephone and email data have helped foil 54 terror plots.
Rep. Adam Schiff, D-Calif., a House Intelligence Committee member, said while he takes the threat seriously he hasn't seen any evidence linking the latest warnings to that agency's collection of "vast amounts of domestic data."