U.S. Raises Airline Threat Level to Highest Level

Published August 10, 2006 at 8:03 AM EDT

WASHINGTON (AP) -- The United States issued its highest terrorism alert for commercial flights from Britain and raised security on all domestic and international flights after a major terror plot was foiled in London. The Bush administration said the scheme was "suggestive of an al-Qaida plot."

"We were really getting quite close to the execution phase," Homeland Security Secretary Michael Chertoff said at a news conference with FBI Director Robert Mueller and Attorney General Alberto Gonzales.

Terrorists had targeted United, American and Continental Air Lines, two U.S. counterrorism officials said. The plot envisioned mid-flight explosions on multiple aircraft using bomb components brought on board in benign state and combined once the planes were aloft, officials said.

The plot was aimed at flights to New York, Washington and California, all major summer tourist destinations, officials said.

The administration raised the threat level for flights from Britain to "red," designating a severe risk of terrorist attacks.

All other flights, including all domestic flights in the United States, were put under an "orange," alert -- one step below the highest level.

Heightened security caused long lines and delays at airport security checkpoints. The government banned passengers from carrying all liquids and gels, including toothpaste, makeup, suntan lotion. Baby formula and medicines were exempted.

"We are taking some very serious and inconvenient measures," Chertoff said. He said it was advisable to have more protection and scale it back, then not to act at all.

Chertoff said there was no indication of plotting in the United States but said officials cannot assume that the terror operation in Britain had been completely thwarted. He said the plot appeared to be engineered by al-Qaida, the terrorist group that carried out the Sept. 11, 2001, attack against the United States.

"It was sophisticated, it had a lot of members and it was international in scope," said Chertoff. "It was in some respects suggestive of an al-Qaida plot."

He added, however, that "because the investigation is still under way we cannot yet form a definitive conclusion."

Gonzales said the operation could "potentially kill hundreds of innocent people." Britain said 21 people had been arrested, including the alleged "main players" in the plot.

Mueller also pointed at al-Qaida. "This had the earmarks of an al-Qaida plot," he said.

The alleged plot was "as sophisticated as any we have seen in recent years as far as terrorism is concerned," Chertoff said.

He said there was no indication of any plotting in the United States but that the government was taking steps to protect against unseen threats or copycat attacks. "We cannot assume that this threat has been completely thwarted," the secretary said.

"There's sufficient uncertainty as to whether the British have scooped up everybody," Chertoff added. Gonzales said the operation could "potentially kill hundreds of innocent people." Chertoff said the plot was "as sophisticated as any we have seen in recent years as far as terrorism is concerned."

Hastily printed signs were posted at major airports warning passengers in red capital letters, "No liquid or gels permitted beyond security."

It is the first time the red alert level in the Homeland Security warning system has been invoked, although there have been brief periods in the past when the orange level was applied.

Homeland Security defines the red alert as designating a "severe risk of terrorist attacks."

There were no commercial passenger planes in the air from Britain to the United States when the red alert was issued, FAA Administrator Marion Blakey said. She said three cargo planes aloft from London -- two Lufthansa and one UPS plane -- were allowed to continue because the threat was focused on passenger planes.

Officials said the government has been aware of the nature of the threat for several days, and President Bush, vacationing in Texas, was fully briefed. Prime Minister Tony Blair's office said in London that the prime minister, vacationing in the Caribbean, had briefed Bush overnight.

The U.S. Northern Command, the military headquarters established in response to the Sept. 11, 2001 attacks, was "monitoring and ... a little bit more vigilant today," said spokesman Michael Kucharek, declining to be more specific.

"I'm not going to say it's business as usual," he said. "We're looking at all sources of information - this is a real threat to the nation."

The plot was not believed to be connected to a group of Egyptian students who disappeared in the United States more than a week ago before reaching a college they were supposed to attend in Montana.

Three of the 11 have since been found and the FBI has said neither they nor the still-missing eight are believed to be a threat.

As part of the foiled Bojinka Plot to blow up 12 Western airliners simultaneously over the Pacific Ocean in the mid-1990s, terrorist mastermind Ramzi Youssef planned to put together an improvised bomb using liquid in a contact lens solution container.

The metal detector and X-ray machines at airport security checkpoints cannot detect such explosives. At many, but not all airport checkpoints, the TSA has deployed walkthrough "sniffer" or "puffer" machines that can detect explosives residue.