The directors of the CIA and FBI say the al-Qaida terrorist organization remains a serious threat to the United States.
In testimony before the Senate Select Committee on Intelligence, Mr. Tenet said information points to the possibility of terrorist attacks in the United States and abroad.
"The information we have points to plots, aimed at targets on two fronts, in the United States and on the Arabian peninsula. It points to plots timed to occur as early as the end of the Hajj, which occurs late this week, and it points to plots that could include the use of a radiological dispersion device, as well as poisons and chemicals," Mr. Tenet said.
The latest intelligence, Mr. Tenet said, "is not idle chatter." He said the United States and its allies have thwarted a number of al-Qaida plots, but al-Qaida may try to strike more vulnerable targets.
Mr. Tenet also said there are disturbing signs that al-Qaida continues to have a presence in Afghanistan, as well as Pakistan, Iran, and Iraq.
FBI Director Robert Mueller said the al-Qaida network will remain, for the foreseeable future, the most immediate and serious threat facing the United States. He is most concerned about Islamic extremists within the United States, potentially numbering several hundred, who have so far gone undetected.
"Our greatest threat is from al-Qaida cells in the United States that we have not yet been able to identify. Finding and rooting out al-Qaida members once they have entered the United States and have had time to establish themselves is our most serious intelligence and law enforcement challenge," Mr. Mueller said.
Mr. Mueller and Mr. Tenet say information sharing between the FBI and CIA has improved since the September 2001 terrorist attacks. However, some lawmakers are not convinced.
Senator John Edwards, a Democrat who is running for President in 2004, announced he is introducing legislation that would withdraw domestic intelligence gathering and analysis from the FBI, and create a new government agency for that purpose.
Mr. Mueller took exception to Mr. Edwards' proposal. He told the committee, "Senator, you have overlooked a great deal of the good work that the FBI has done in the last 17 months in analyzing information and putting it to use."
Referring to criticism of the intelligence community, the committee Chairman, Pat Roberts, said he will be watching the FBI and CIA closely.
"As chairman of this committee, I intend to conduct vigorous oversight of the intelligence community to ensure that it provides our leaders with the quality of intelligence they need to ensure the security of the American people, whether at home or abroad," Mr. Robert said.
The testimony on Capitol Hill coincided with a recent upgrading of the national terrorist threat level from "elevated" to "high."