ZARIT, Israel-Lebanon border — A few hundred yards north of an army watchtower marking Israel’s northern border with Lebanon, Israeli sappers yesterday organized a leaving present for Hezbollah.

A countdown, a few radio calls, and then a huge explosion. Israeli soldiers may be pulling out of Lebanon, but they are not going quietly.

Rising within a small mushroom cloud, debris was thrown into the air before the roar of the blast hit home. What had been a network of Hezbollah tunnels within Kalashnikov range of Israeli homes was reduced to a crumpled concrete wreckage.

According to senior Israeli commanders, just a few hundred soldiers remain in Lebanon. During Israel’s final push on the last weekend of the war, in mid-August, they claimed to have 30,000 troops there. Now, the majority have gone home, handing over positions up to 18 miles into Lebanon to U.N. forces and soldiers from the Lebanon army.

Despite earlier promising that the remaining troops would be home by the weekend, and in time for the Jewish New Year, Israel’s army chief, Lieutenant General Dan Halutz, yesterday said there were “issues to be wrapped up.”

That is bad news for those who remain. Many are young crew members of Merkava tanks, holding position while waiting to hand over to the U.N.monitoring force Unifil.

“The general idea is to keep the space empty until the U.N.arrives,” a tank gunner, Corporal Eliav Pollack, who had just returned from a four-day mission into Lebanon, said. “You pick a hilltop [for] a fixed ambush — it’s like a stakeout.”