Southern Lebanon faces dire drinking water and fuel shortages which threaten the outbreak of epidemics if Israel keeps up attacks on the country, a senior U.N. official warned on Friday.

"The situation is getting desperate. If shortages continue we may be witnessing outbreaks," Paul Sherlock, a New York-based senior advisor for emergencies on water and sanitary in the U.N. Children's Fund (UNICEF), told Agence France Presse.

The Israeli offensive has left more than 900 people killed, 3,000 wounded and nearly a million others displaced — many of them stranded in schools and public gardens. But conditions are most extreme across the south where the attacks have cut off roads and bridges and many villages have been isolated and are pleading for food, water and medicines.

"The most vulnerable areas are in southern Lebanon, mostly in border villages where people have been staying in basements for over 15 days. There is no water, no power, no fuel, no sewage," said Sherlock.

"There are reports that babies are given water to drink from rivers," he said. "We fear bloody diarrhea, cholera and other epidemics. But what we fear most is bloody diarrhea, especially for children under five years old," he said.

"Our biggest fear is hygiene. It is very hot and people are reduced to the point where they are not being able to wash themselves, or their hands," he said.

Jennifer Pagonis, a spokeswoman for the office of the UN High Commissioner for Refugees UNHCR, said Friday that Israeli bombings on bridges cut off an "umbilical cord" for relief supplies and halted evacuations through Syria.

The attacks were apparently aimed at further isolating Lebanon, which has been under strict sea and air blockade since Israel launched the onslaught on July 12 after Hezbollah captured two soldiers at the border.

President Emile Lahoud condemned the bombardments as an attempt to "break the communications between the sons of the same country in order to starve them and put pressure on them."