At least 350,000 unexploded bomblets from Israeli cluster bomb attacks litter fields, homes, schools, hospitals and playgrounds in southern Lebanon and could take up to two and a half years to clear, the U.N. said in a report released Tuesday.

David Shearer, U.N. Humanitarian Coordinator in Lebanon, said it was "outrageous" that Israel had fired 90 percent of the munitions in the last 72 hours of the conflict when the U.N-brokered cease-fire agreement was almost in place.

Israel could greatly accelerate the clearance effort handing over strike coordinates but has not done so, he said.

"What we'd like is the number of shells that were fired in and the actual coordinates so we can go in and short-circuit what we're doing now and go and find those munitions straight away. But that has not happened yet," Shearer told reporters.

"We have asked for them but they have't yet been forthcoming. I haven't heard any explanation," the U.N. official said.

Israeli government spokeswoman Miri Eisin said she was unaware of any official U.N. complaint over cluster bomb mapping.

Dalya Farran, spokeswoman for the U.N. Mine Action Coordination Center in the southern city of Tyre, said Israel had handed the U.N. center some maps of cluster bomb strikes in Lebanon.

"But they're useless, they don't have any coordinates or legend," Farran said by telephone from Tyre.

The fist-sized bomblets, leftovers from the 34-day Israeli offensive against Hezbollah militants, have killed or wounded on average three people daily since the Aug. 14 truce, according to the U.N demining center.

At least 15 people including a child have been killed and 83 others wounded, 23 of them children, it said.

So far, U.N. demining teams have identified 516 cluster bomb strike locations and cleared 17,000 bomblets.

The failure rate of the Israeli cluster bombs was around 30 to 40 percent and the density of cluster munitions in south Lebanon is higher than witnessed in Kosovo or Iraq, with a greater concentration in built-up areas, according to the U.N.

Israel fired rockets with multiple cluster bombs. The estimate of 350,000 unexploded munitions excludes cluster bomb firings by conventional artillery or dropped by Israeli aircraft.

Shearer said apart from the human cost of the cluster bombs, they were having a severe economic impact on southern Lebanon, a poor region which is 70 percent dependent on agriculture.

Farmers were unable to get to their land to irrigate or harvest their current crop or to plant next year's crop. Because substantial numbers of cluster bombs were likely not to be cleared until the end of 2007, next year's agricultural cycle will also be affected.

"The south is comparatively the poorest area in Lebanon. The cluster munitions are stopping farmers from getting out into their fields and resuming farming activities," Shearer said. (AP)