Hunter did say he is confident the attack was not domestic, as was the case with the Oklahoma City bombing.
Hunter, vice chairman of the House Armed Services Committee, said of the attacks Tuesday, "This was a military operation that required tremendous forces, a lot of money and a lot of technology."
Hunter's comments came as authorities in the Imperial Valley remained on high alert.
Lauren Mack, spokeswoman for the U.S. Immigration and Naturalization Service, said late Tuesday ports of entry all along the border would remain open but on alert.
She said there had been rumors broadcast by media that the ports were closing but that was never the case.
Still, there were indications such rumors affected the Port of Entry in downtown Calexico, where there were fewer vehicles and light foot traffic.
Mack said she was unsure how long the ports would remain on alert, but there were no indications the situation would change as of presstime.
Imperial Valley Blood Services will have blood drives from 1 to 7 tonight and Thursday and 8 a.m. to noon Friday at Pioneers Memorial Hospital in Brawley.
Trish Burich-McNeece, coordinator for local blood services, said she has received several calls from those wishing to donate blood for the victims of the attacks. She said a portion of the blood will go to help those victims.
Burich-McNeece added a military transport in San Diego flew 480 units of blood to New York on Tuesday. That blood was provided by the San Diego Blood Bank, with which the Imperial Valley Blood Services is affiliated.
In other developments on Tuesday, the Holtville Unified School District evacuated students from each school in the district after an anonymous bomb threat was phoned into the district.
Only students at Holtville High School were allowed to return to classes before the day's end.
Authorities from the Holtville police and fire departments, the county Sheriff's Office, the California Highway Patrol, the county Fire Department and county bomb squads responded to each of the schools.
No bombs were found, and one county fire official speculated it was a "copycat" threat in light of the day's terrorist attacks.
As a state of alert continued throughout the day, a bomb sweep was done at the Imperial County Airport, which remained closed as part of an action by the Federal Aviation Administration to stop all flights in and out of the country.
There were reports flights might be allowed to restart at 12:30 today.
Imperial County Fire Chief Joe Buzo, coordinator for the county Office of Emergency Services, said actions taken Tuesday were standard precautionary steps in light of the attacks against the country.
He said both El Centro Regional Medical Center and Pioneers were placed on lock-down status, which meant the number of entryways into the hospitals were reduced and more security was added at entrances.
Naval Air Facility El Centro, along with military bases throughout the nation, was on the Navy's highest alert status Tuesday, which meant access on and off the base was restricted.
Authorities at the Navy base referred calls from the media to a Navy communications office in Los Angeles. Officials there declined to comment whether crews or resources would be sent from any base to the areas where the terrorist attacks occurred.
Back in Washington, D.C., Hunter described the capital as a ghost town.
He said the attack was not going to shut down the U.S. government, but it likely would bring changes.
"It will be difficult to maintain all the freedoms in the face of terrorism," he said. "Still, our national government has to remain accessible."
He said as the nation starts to heal and recover from the attacks, the country will come back strongly.
"We are going to find the people who did this; find the organization and destroy it," he said.
Staff Writer Darren Simon can be reached at 337-4082.