JERUSALEM (Reuters) - Four weeks into an offensive that has failed to stop Hezbollah rocket attacks, the Israeli military has changed a top commander of its Lebanon war effort in a blow to the pride of the Middle East's mightiest army.

Despite losing nearly 70 soldiers in the offensive, Israel's security cabinet decided on Wednesday to expand the operation which could see up to 20,000 more troops sent in and a push as far north as the Litani river, 20 km (13 miles) inside Lebanon.

Israeli military affairs commentators predicted on Wednesday the dramatic move would hurt morale in the army's highest ranks and on the frontline.

In a surprise step on Tuesday, the army's chief of staff appointed Major-General Moshe Kaplinsky "to coordinate operations in Lebanon" and serve as his "representative" in the headquarters of Northern Command chief Major-General Udi Adam.

Adam has been the top commander of the Lebanon front.

So far, at least 10,000 troops have been fighting just inside Lebanon, meeting fierce resistance from Hezbollah.

Widened offensive carries risks for Israel

Analysts said Israel's decision to expand operation would not defeat the guerrilla group and might leave Israel more exposed.

"The bottom line is that Israel cannot claim a military victory in any form," said Nadim Shehadi, a Middle East expert at British foreign affairs group Chatham House.

"The only chance that Israel and the United States have of coming out with a positive result is a political solution within Lebanon in which Hezbollah is disarmed," he said, linking that political solution to a pending UN resolution on the crisis.

With the Israeli population expressing distress that more has not been achieved in four weeks of fighting the government and army are keen to show they can get results.

Israeli officials have told Western diplomats they hope an expanded offensive will increase Israel's leverage as the United Nations weighs a resolution, probably this week, on the deployment of an international force to southern Lebanon.

"They want to increase pressure on the international community to deploy a force," one Western diplomat briefed by the Israelis told Reuters, adding that Israel saw its broader offensive as a "parallel process" to the UN discussions.

Another Western diplomat said Israel had indicated it was prepared to halt the widened operation after a few days if an agreement was reached at the United Nations calling for an end to military operations.

A UN vote is not expected to take place before Thursday because of disagreement over its contents, including whether Israeli forces should withdraw from Lebanon before or after an international force deploys.

Shehadi sees Israel's fixation on the military option as old-style thinking that will only make things harder for the Jewish state, not just in terms of securing a victory, but in terms of increased loss of life in both Israel and Lebanon.

"It's like quicksand. The deeper they go in militarily, the harder it's going to get. The more they rely on the military option, the less success there will be," he said.

Gidi Grinstein, a former Israeli government negotiator who now heads his own research institute, also sees problems with a dependence on military might if it can't get results.

"Unless you have an overwhelming military victory against a guerrilla group, then you don't have a victory at all," he said, while also not dismissing the potential for a broader offensive to achieve something beyond what's been gained so far.

"If Israel finds itself stuck in Lebanon with a standing army, then Hezbollah will be in its comfort zone," he added.

For Grinstein, the greater concern is the terms of the UN resolution.

If it ends up creating a window of time between a ceasefire being called, an Israeli withdrawal from Lebanon and the deployment of an international force, then Israel could end up with next to nothing to show from weeks of combat.

"A significant window -- and I mean weeks -- would erase all the military gains Israel has made," he said.

"The speed of deployment of an international force is critical to solidifying what Israel has tried to do militarily. But the prospect of having a significant international force on the ground is slim."

11 Israeli soldiers killed in Lebanon: TV

Eleven Israeli soldiers were killed in heavy clashes with Hezbollah fighters in south Lebanon Wednesday, Al-Jazeera Arab news channel reported.

The television did not immediately give further details.

But a news source at the station told AFP that, according to Al-Jazeera's sources on the ground, four soldiers were killed in fighting in the border villages of Aita ash-Shaab and Taibeh and seven others in the village of Debel.

Al-Arabiya television earlier reported that four Israeli soldiers were killed in a rocket attack in Aita ash-Shaab.

The Israeli army has not confirmed the deaths. A spokeswoman had said earlier that 15 Israeli soldiers had been "hit" in fierce clashes with Hezbollah fighters in south Lebanon as the conflict entered its fifth week.

New Israeli strikes rattle funeral in Beirut suburbs

The Israeli military launched new strikes on Beirut's southern suburbs Wednesday, with hundreds of mourners burying their dead from a previous raid running for cover.

A first strike of two bombs on the area's main throughfare and another broadside of five bombs forced pallbearers to abandon their coffins at graveside and run for cover.

They were burying 26 of the 32 dead from Monday's attack on the district of Shiyah, still inhabited by many residents after being spared earlier raids.

Thick plumes of grey smoke billowed into the sky after the attacks, the latest in a string of strikes on the Hezbollah stronghold area, an AFP correspondent reported.

U.S., France in new Mideast resolution talks

The UN ambassadors for France and the United States held new talks Wednesday in a bid to overcome divisions on a Security Council resolution calling for an end to hostilities in Lebanon, a diplomat said.

The two sides are seeking agreement on whether to change their proposed joint resolution to integrate Lebanese demands that the Security Council call for an Israeli withdrawal from southern Lebanon.

The diplomat did not say if ambassadors John Bolton of the United States and Jean-Marc de La Sabliere of France had made any progress.

The two are haggling over a new text that the French envoy has said he hopes will be passed by the end of the week.

"It seems indeed that there are American reservations towards adopting the proposal" integrating certain Lebanese demands, French President Jacques Chirac said earlier Wednesday.

Chirac has hinted that France may press ahead alone and submit a resolution to the Security Council, with or without U.S. support.

Aid agencies facing 'logistical nightmare': Oxfam

British aid agency Oxfam said Wednesday it was facing huge obstacles in delivering humanitarian aid to Lebanese people hardest-hit by the Israeli bombardment.

The international development, relief and campaigning organization said the humanitarian situation in Lebanon was "appalling" and it was restricted to operating only in the capital Beirut due to fears of their trucks being targeted by Israeli warplanes.

Ian Bray, Oxfam's spokesman on humanitarian emergencies, told AFP that hospitals in southern Lebanon were beginning to run out of fuel.

"There are huge challenges to get aid into areas where there is greatest need, which is in the south," he said.

"There are attacks on any movement. We are getting reports that truck drivers are refusing to work because they are afraid of being hit by Israeli missiles -- that is causing a huge problem.

"The bombing of roads and infrastructure will hamper any aid effort, even if we sort out the security.

"Hospitals are soon running out of fuel, so getting fuel around that road network is going to be a logistical nightmare."