Israel says the Palestinians in Rafah are trying to import more powerful weapons than before, like shoulder-held missiles that could bring down a plane, and Katyusha rockets that could reach deep into Israel.
Hezbollah fighters use tunnels to quickly emerge from the ground, fire a shoulder-held antitank missile, and then disappear again, much the way Chechen rebels used the sewer system of Grozny to attack Russian armored columns.
As at other airports, there was serious worry about such things as the threat of a terrorist climbing the chain-link fence to lurk in the woods and bring down a plane with a shoulder-held antiaircraft missile.
The shoulder-held anti-aircraft missiles are of the same type used by Afghan guerrillas to shoot down Soviet aircraft.
American aid to the guerrillas has in the past included automatic weapons, ammunition and shoulder-held anti-aircraft missiles, like Stingers.
Tons of weaponry, including thousands of shoulder-held surface-to-air missiles, has been stolen from Gaddafi's abandoned depots since his regime was overthrown by rebel forces in August.
And within a month Chadians expect to receive Stinger missiles -the advanced, shoulder-held anti-aircraft missiles Afghan guerrillas have used to shoot down Soviet aircraft.
Its planes are vulnerable to shoulder-held missiles and other relatively simple air defense systems.
Later, a Mi-17 helicopter was shot down by a shoulder-held missile with the loss of all its crew.
In March 2004, Israeli police arrested four suspected contract killers from Belarus who had been found with weapons, including explosives and shoulder-held missiles, at their hideout.