Ben-Gurion Airport manager Shmuel Kandel says that fuel discovered to be contaminated that would have been used by Israeli aircraft has been sent for laboratory analysis, and testing has revealed that the cause of the contamination was not sabotage or terrorism. However, the source of the pollutant is still unknown at this time, Kandel said.

Commercial air traffic out of Israel was shut down yesterday after airplane fuel at Ben-Gurion International Airport was found to be contaminated. From 1 P.M. all flights out of the country were halted, stranding tens of thousands of passengers.

Domestic flights were also grounded, halting air service to Eilat. Interim arrangements were being made to bring other fuel stocks to the airport to enable aircraft to take off with limited fuel, requiring a refueling stop prior to reaching their final destinations.

The shut-down initially affected primarily flights to Europe, waylaying, among others, fans en route to Barcelona to watch the Maccabi Tel Aviv basketball team compete in the Euroleague Final Four. Incoming flights from abroad were forced to make a stop at nearby airports such as Amman in Jordan and Larnaca, Cyprus for refueling.

Kandel ordered a halt to the refueling of aircraft after getting word from the firm Aviation Assets, a Paz subsidiary, which supplies fuel to the airport's fuel pipeline, that it had found contaminants in the fuel. Fueling of aircraft at the country's other domestic airports was also halted.

Initial concerns about aircraft fuel supplies arose about two weeks ago, when it was noticed that the fuel filters on trucks supplying fuel to aircraft were clogging.

Concerns have been expressed, however, that the contamination problem has affected not just fuel supplied to the airport but is a more widespread in the country's fuel supply.

In anticipation of a resumption of air traffic at Ben-Gurion Airport, extra border control personnel were brought in overnight to handle the expected crush. Many travelers who had already gone through passport control chose to spend time in the duty free shops, despite the uncertainty over when flights would resume.

"This is a serious matter," Transportation Minister Yisrael Katz said yesterday, adding that he ordered an immediate investigation. He said the process of emptying the fuel tanks on planes that had received the suspect fuel had begun, and fuel from the Pi Glilot fuel storage facility was being brought in to replace it. Priority was being given to planes that had not been refueled, Katz said. The planes would be given enough fuel to reach a nearby foreign airport, where they would take on additional fuel. National Infrastructure Minister Uzi Landau also ordered his ministry to investigate.

Defense officials, including officials from the Shin Bet security service, confirmed that no evidence has been found of sabotage as a cause of the contamination, but security sources said the most recent incident is the latest in a string of serious mishaps concerning the country's strategic infrastructure. The problems, they said, should set off alarm bells.

Regular supply of fuel in the country is the responsibility of the National Infrastructure Ministry, while supplying fuel during times of national emergency is delegated to the Defense Ministry. The Israel Air Force uses fuel supplies that are entirely separate from the sources used in the civil aviation sector. An air force source said the IAF's fuel supplies have been checked and confirmed to be free of contaminants.

El Al Israel Airlines announced the cancellation of 20 departing and arriving international and domestic flights yesterday as a result of the fuel contamination problem. The scrapped flights included services to New York as well as London, Moscow and other European destinations. El Al said affected passengers would receive a refund or could opt to fly on future flights to any destination in the same region of the world. "The company is working to find a solution for its passengers as quickly as possible, and will continue to provide updates," an airline spokesman said yesterday.

Arkia Airlines announced the cancellation yesterday of 12 domestic flights on its route to and from Eilat, saying it would provide its passengers with transportation by road. Arkia also canceled flights to Rome and Poland.

Concern over contamination of jet fuel is motivated by the fact that it can cause airplane engines to stall. Foreign particles in jet fuel can clog fuel filters and damage aircraft engines. Contaminants in airplane fuel can also promote the growth of bacteria in the fuel tank that can cause fuel clogs. Although the source of the current contamination problem is unknown, possible sources include the contamination of fuel supplies before the fuel reached Ben-Gurion Airport.

There were reports of contamination of bus and truck fuel elsewhere in the country in recent weeks, affected by an unidentified oily substance clogging the vehicles' fuel filters. The Egged bus cooperative, for example, had fuel tested after receiving reports that the filters on its buses had been clogged and that fuel filters had been ruined. The Nes Tziona Institute for Biological Research was enlisted two days ago to test samples from a fuel depot in the center of the country. Yesterday steps were taken to use stocks in the country's strategic emergency reserves, at this point for airplane fueling only.

In April 2005, after a contaminant was found in jet fuel, aircraft from El Al and foreign carriers were grounded for several hours. The aircraft were then required to make refueling stops elsewhere. After additional inspections at the time of that incident found the fuel again met standards, traffic at the airport returned to normal.