QUICK ACTION BY PASSENGERS HALTED ATTACK (See also TERROR-SUSPECT and TERROR-SECURITY) Reporting was contributed by Eric Schmitt in Washington, Sarah Lyall in London, Micheline Maynard and Nick Bunkley in Detroit, and Matthew L. Wald in Sarasota, Fla. Despite the billions of dollars spent since 2001 on intelligence and counterterrorism programs, sophisticated airport scanners and elaborate watch lists, it was something simpler that averted disaster on a Christmas Day flight to Detroit: alert and courageous passengers and crew members. During 19 hours of travel, aboard two flights across three continents, law enforcement officials said, Umar Farouk Abdulmutallab bided his time. Then, just as Northwest Flight 253 began its final approach to Detroit around noon on Friday, he tried to ignite the incendiary powder mixture he had taped to his leg, they said. There were popping sounds, smoke and a commotion as passengers cried out in alarm and tried to see what was happening. One woman shouted, 'What are you doing?' and another called out, 'Fire!' And then just as occurred in 2001 when Richard C. Reid tried to ignite plastic explosives hidden in his shoe on a trans-Atlantic flight, fellow passengers jumped on Abdulmutallab, restraining the 23-year-old Nigerian. Jasper Schuringa, a Dutch film director seated in the same row as Abdulmutallab but on the other side of the aircraft, said he saw what looked like an object on fire in the suspect's lap and 'freaked,' he told CNN. 'Without any hesitation, I just jumped over all the seats,' Schuringa said, in an account that other passengers confirmed. 'I was thinking, Oh, he's trying to blow up the plane. I was trying to search his body for any explosive. I took some kind of object that was already melting and smoking, and I tried to put out the fire and when I did that I was also restraining the suspect.' Schuringa said he had burned his hands slightly as he grappled with Abdulmutallab, aided by other passengers, and began to shout for water. 'But then the fire was getting worse, so I grabbed the suspect out of the seat,' Schuringa said. Flight attendants ran up with fire extinguishers, doused the flames and helped Schuringa walk Abdulmutallab to first class, where he was stripped, searched and locked in handcuffs. 'The whole plane was screaming -- but the suspect, he didn't say a word,' Schuringa said. He shrugged off praise for his swift action, which he said was reflexive. 'When you hear a pop on the plane, you're awake, trust me,' he said. 'I just jumped. I didn't think. I went over there and tried to save the plane.' The close call was followed by several tense hours as counterterrorism officials checked on other U.S.-bound flights to determine whether more planes were targets, as in the thwarted 2006 plot to smuggle liquid explosives aboard multiple flights leaving from Britain. They found no immediate signs that other flights were in danger, officials said. They tightened airport security, ordering new restrictions on carry-on luggage and passenger movement inside the cabin, but did not elevate the nation's overall threat level, which has been at orange since 2006. Dozens of investigators led by the Federal Bureau of Investigation were working Saturday to understand exactly how a passenger managed to get flammable powder and a syringe of chemicals aboard the flight and what the implications might be for air safety at a time of heavy holiday travel. Intelligence agencies were studying intercepted communications to see whether clues were missed and to assess whether the incident could presage more attacks. Richard Griffith, 41, of Pontiac, Mich., who said he had been sitting in the back of the plane during the episode, praised the crew for its professionalism in preventing panic. Griffith said the passenger who had been sitting next to the suspect told him the suspect got up once midflight to use the bathroom and returned to the bathroom about 20 or 30 minutes before the incident, apparently to brush his teeth. Otherwise, he said, 'He just sat there, he didn't talk to nobody.' The episode, which riveted the attention of President Barack Obama on vacation in Hawaii and prompted dozens of counterterrorism officials to rush back to work, capped a year in which plots of violence inside the United States surged. The near-miss aboard a plane loaded with 289 people appeared to underscore the continuing determination of Muslim militants to kill Americans more than eight years after the Sept. 11 attacks. Bruce Hoffman, who studies terrorism at Georgetown University, said it was at least the tenth plot or attempt at 'jihadi violence aimed at the United States' in 2009, a number he said was at least triple the average for recent years. Hoffman noted the timing of the attack -- Christmas -- for some Muslim extremists a day known as 'the crusaders' holiday,' he said. Passengers transferring from foreign flights at the Amsterdam airport are required to be screened by security there before taking off for another flight, an airport spokeswoman said Saturday. She could not confirm the details in Abdulmutallab's case but said he was presumably subject to screening before he boarded the plane for the United States. Investigators planned to interview all the passengers on the suspect's flights and to review any security-camera video footage of him, a law enforcement official said. Abdulmutallab apparently left Murtala Muhammed Airport in Lagos aboard KLM flight 588, a Boeing 777, at 11 Christmas Eve and arrived at Schiphol Airport in Amsterdam a little early, at 5:37 a.m. on Christmas Day. Three hours later, at 8:54 a.m., Northwest 253, an Airbus A330, took off for Detroit Metropolitan Wayne County Airport, with three pilots, eight flight attendants and the 278 passengers. Amsterdam has long been an airport of concern for U.S. aviation security officials, like other major gateways in Europe, including London, Brussels and Frankfurt, where the TSA monitors note an unusually large number of people on so-called 'selectee' or 'no-fly' lists associated with security threats, one former senior Homeland Security official said. As a result of such concerns, U.S.-bound flights from these cities are more likely to have air marshals aboard -- teams that typically travel in pairs. But that apparently was not the case on Northwest 253, said Edmund S. Hawley, who served as administrator for the Transportation Security Administration until January 2009. If the air marshals were present, they would certainly have broken their cover and apprehended the suspect, Hawley said. Hawley, who coordinated the response in the United States to the 2006 liquid bomb plot, said this should not be seen as a sign that security has dropped. It was probably just bad luck, he said. 'That doesn't suggest to me they let guard down,' Hawley said. Holiday traffic is too great to have marshals on every plane. In 2007, the Amsterdam airport began testing body-scanning machines that can find threats hidden under a passengers' clothing, but there are only 10 such machines out of 200 security checkpoints at the sprawling airport. In the United States, the TSA has begun to substitute similar machines, called millimeter-wave technology, for walk-through metal detectors. 'Those will pick up anything underneath clothing,' Hawley said. 'If he had it taped to his leg, it could have easily identified something there.' Hawley said of al-Qaida and like-minded militants: 'They have been trying since 2001, and they are going to keep trying. You have to keep your vigilance up over the long term. That is the hard thing.' 