Up to a million unexploded cluster bombs fired by the Israel Defense Forces are now the biggest threat facing civilians in south Lebanon, UN agencies said on Tuesday, adding that it could take more than a year to clear all the ordance from Lebanon.

The agencies said the unexploded bombs litter streets, homes and orchards.

Fourteen people have been killed and 90 wounded by unexploded ordnance since the end of the war in mid-August, with all the fatalities and most of the injuries caused by cluster munitions, the UN Mine Action Coordination Center said.

So far, the Lebanese Army, United Nations peacekeepers, the UN Mine Action Coordination Center and its contractors have cleared almost 40,000 unexploded cluster bombs, but up to a million more remain.

With an estimated 12-15 months needed to clear the south of cluster bombs, they pose mortal danger to displaced civilians returning to their villages after the 34-day war, the UN said.

"The problem now rests with cluster bombs. They get caught up in bushes, in trees, in hedges. They get caught up in wire fences... They are lying in people's houses, in their front gardens," Chris Clark, program manager of the UN Mine Action Coordination Center in southern Lebanon, told a news conference.

"A lot of these cluster bombs, small as they are, are caught up in the rubble and pose a continuing problem to any reconstruction ... but the main problem will be for people who just want to go back to their houses, clear the rubble out and try to restore their lives," Clark added.

Clark said Israel had also yet to provide detailed information on the amounts of cluster bombs fired or the coordinates of the strikes, which would help munitions clearance teams identify the main areas on which to focus their efforts.

The United Nations refugee agency, UNHCR, said some 200,000 Lebanese remained displaced, their return home slowed by the destruction of their houses and by unexploded bombs.

With winter coming up and most people in the south relying on agriculture for their main source of income, the UNHCR is concerned that farmers will be unable to return to their fields, robbing them of their livelihood, or will face a deadly threat if they do as rain sinks the bombs into the soil.

"Displacement which we would have expected to end much more quickly is going to continue for many, many more months to come... We expect that instead of the displacement ending so people can return to their homes in 12 months or so now it could take up to 24 months," UNHCR's Arjun Jain said.

Clark said that Israel fired around 3,000 bombs, rockets and artillery a day into Lebanon in the early days of the war, rising to some 6,000 a day at the end, with around 40 percent of the cluster bombs dropped on the south failing to explode.

Israel denies using cluster bombs illegally.