Top FBI, CIA and Homeland Security Department officials briefed House members Wednesday about a steady stream of intelligence indicating Al Qaeda (search) may seek to mount an attack aimed at disrupting U.S. elections.

All House members were invited to the session at the Rayburn House Office Building with FBI Director Robert Mueller; Asa Hutchinson, Homeland Security undersecretary for border and transportation security; and John Brennan, a CIA official who heads the joint CIA-FBI Terrorism Threat Integration Center (search).

Rep. Christopher Cox, chairman of the House Homeland Security Committee, said he could not discuss specifics of the presentation. But he said there are broad concerns that Al Qaeda wants to strike inside the United States this summer or fall and hopes to influence the U.S. election, as terrorists did in Spain with the deadly Madrid train bombings (search) in March.

"There is a steady drumbeat of reporting and the threat has not abated," Cox, R-Calif., told reporters.

The briefings were requested by congressional leaders, some of whom attended a similar event Tuesday at the White House at the invitation of Andrew Card, President Bush's chief of staff. The Senate was scheduled to hold a similar session Thursday with the FBI and CIA officials as well as Homeland Security Secretary Tom Ridge.

No new intelligence is being presented at the briefings, said two federal law enforcement officials who spoke on condition of anonymity. There is no credible information pointing to a specific time, place or method for a terrorist attack, they said.

Bush administration officials have said Al Qaeda was emboldened by its successful March 11 attack in Spain, which killed 190 people and contributed to the election defeat of the ruling party. Spain subsequently announced it would withdraw troops from Iraq, seen by many analysts as a boon to terrorist goals.

With the Republican and Democratic presidential nominating conventions approaching, many lawmakers asked for briefings about the terror attack threat and the level of security precautions being taken.

The FBI has formed a special task force to respond to the threat, which also prompted the Secret Service to close roads and rail lines and restrict other access around the convention sites. The Democrats will meet at Boston's FleetCenter July 26-July 29, with the GOP convention to be held at Madison Square Garden in New York from Aug. 30-Sept. 2.

Congress is scheduled to leave town this month for the summer and return after Labor Day.