From whispered telephone tip-offs to missiles that can home in on targets as small as a face in a car window, Israel?s hunt for Palestinian militants in the teeming Gaza Strip is a mix of high risk and hi-tech.

Ten Hamas men have died in helicopter ambushes since Israel vowed retaliation for a suicide bombing by the Islamic group that killed 21 people aboard a Jerusalem bus on August 19.

Seasoned by previous campaigns against a 35-month-old Palestinian uprising in the occupied West Bank and Gaza, dozens of Hamas leaders went into hiding. But this time the odds are really against them, Israeli security sources said yesterday.

?We have refined our methods and are confident we can reach those in our 'target bank' with minimum risk to innocents?, a source said, referring to militants slated for attack, although four bystanders have been killed in the recent air strikes.

The names in the ?target bank? are usually common knowledge, particularly in Gaza where Hamas and kindred groups have a high public profile. That means marked militants are especially vulnerable to Israel?s vast network of paid informers, who are themselves likely to be lynched as traitors if discovered.

?Dear mujahed (Islamic fighters), you are being watched closely around the clock. It could be the store owner, or your neighbour, or someone in a car?, read a Hamas directive issued last week after the group?s deputy political chief was killed.

Death traps and dye

When an informer phones in a sighting, Israeli security sources said, it is correlated with other tip-offs and surveillance drones. Often F-16 jets pitch in, roaring over- head to mask the clatter of Apache or Cobra helicopter gunships hovering on the horizon, missiles ready for launch.

Militants are invariably hit while in their vehicles, along with drivers and bodyguards. But mobility can cause problems for missiles designed to be used against slow-moving tanks. To ease tracking, collaborators sometimes dab the militant's vehicle with a dye invisible to the eye but easily picked up by the sensors of Israeli helicopters.

Israel long favoured the US-made Hellfire missile, which spurts molten metal on impact. But Hellfires killed so many bystanders during the last hunt for Hamas, in June, that the top brass decided to switch to a classified Israeli-made missile. ?The new weapon allows us to choose a warhead suited to the target, which means limited collateral damage?, a source said.

And while Hellfires require that targets be ?lit? by laser-wielding agents on the ground, the Israeli-made missile has a camera in its nose which makes for real-time aiming.

?The guy controlling the missile sees exactly where the missile is going and guides it right to the window of the target car if necessary?, Robert Hewson, editor of Jane's Air-Launched Weapons said. ?It can also be aborted should the target prove to be the wrong one.?

Finger on panic button, the pilot reports back to base on what the missile ?sees?. ?We can abort up to a couple seconds before impact. On occasion the terrorist's face shows up on camera for final confirmation?, said an Israeli security source.

Four bystanders have been killed and two dozen wounded in Israel's latest missile strikes, which Palestinian officials called a broadside against foundering peace hopes. Israeli officials blamed militants for operating in populated areas.

Dan Williams

Beirut

Hizbollah fires at Israeli jets over Lebanon

Lebanon's Hizbollah guerrilla group said its gunners fired anti-aircraft rounds yesterday at Israeli jets that roared over southern Lebanon.

"The air defence units of the Islamic Resistance challenged... Zionist enemy war planes that violated Lebanese sovereignty over the areas of Marayoun, Hasbaya and Khiam in the Lebanese south," a statement from the Shi'ite Muslim group said. Residents said Israeli jets broke the sound barrier over some parts of the south and the eastern Bekaa Valley. No planes were reported hit.

Earlier this month, Hizbollah anti-aircraft fire killed an Israeli teenager in northern Israel, drawing Israeli air strikes on the outskirts of south Lebanese villages. That fatality was the first in northern Israel by Hizbollah fire since Israeli forces withdrew from southern Lebanon in 2000 after a 22-year occupation. Since then Israeli planes have regularly flown into Lebanese skies, drawing Hizbollah barrages. The United Nations views both overflights and Hizbollah's reaction as a violation of the terms of Israel's pullout. Tensions between Israel and Hizbollah, which is backed by Syria and Iran, surged after Hizbollah chief Sheikh Hassan Nasrallah threatened last month to kidnap more Israelis unless there was progress on stalled prisoner swap talks.

Since then, Israel has handed over the remains of two Lebanese Hizbollah members killed fighting Israel, described as a possible precursor to a prisoner swap deal by an analyst.