Beirut:  One hospital in the heart of Beirut will stop taking in new patients while another in the south - full of war wounded - expects to close soon.

Shortage of medicines and generator fuel are acute across this battered country and supplies of milk, rice and sugar are low. Now, with the Israeli bombing of the last highway to the outside world, more shortages are sure to come.

"This is Lebanon's umbilical cord," Christiane Berthiaume of the World Food Programme said of the four key bridges destroyed along Beirut's main access road to the north - the last major resupply link to Syria.

"This (road) has been the only way for us to bring in aid. We really need to find other ways to bring relief in. It is a real catastrophe," warned Dr. Gassan Hammoud, who runs a 320-bed hospital in the southern port city of Sidon which he says may have to shut down within 10 days.

The Hammoud Hospital, he said, is filled with wounded from the fighting in southern Lebanon and is already operating on dwindling medical supplies and acute fuel shortages.

"I expect the situation to get much worse, after what happened today," Hammoud said.

Significantly broadening their bombing campaign, Israeli airstrikes on Friday destroyed four bridges on the main north-south coastal highway linking Beirut to Syria.

An Israeli naval blockade -- along with earlier strikes against the road to the eastern border and the capital's international airport -- have closed off other access points.

Dr. George Tomey, acting president of the American University of Beirut, said the university's medical centre will stop receiving new patients as of Monday, except for emergency cases.

"We have reached a very critical stage," he said of shrinking medical and gasoline supplies. Many hospital staff were too scared to report to work, he said, while others could not get to work because of gasoline shortages.

"As of Monday, if the situation remains like this, we're going to close most of the hospital and keep only the operating rooms and emergency units functioning. Only critical patients will be admitted," he said.

Tomey, who has been at the university for 42 years and lived through Lebanon's 1975-90 civil war, said the situation is the worst he's seen.

"It's very sad. We have never had to close the hospital, not even during the worst days of the civil war," he said.

President Emile Lahoud accused Israel of waging a "war of starvation" against Lebanese civilians.

"It is an aggression that has exceeded Israel's declared objectives. Israel has now decided to destroy Lebanon," he said in a statement.

Israel's naval blockade has kept fuel tankers from reaching Lebanon, leading to gasoline shortages.

Across the country, long lines of cars form at gas stations where drivers are only allowed to buy a maximum of 2.5 gallons (9.5 litres) of gas.

Essential medicines, including blood pressure and diabetes medications, are in short supply and grocery stores have run out of essentials such as milk, diapers, baby food and canned goods. They also report shrinking supplies of basic staples like rice and sugar.

Electricity cuts are getting worse, with some areas getting only two hours of electricity a day. Candles and batteries have become a rare commodity in supermarkets and stores.

Hammoud said his hospital was receiving just six hours of electricity a day and he has only a week's worth of fuel for the backup generator.

"We are rationing medicines, we're already canceling or postponing non-urgent operations, taking only the critical cases," he said.

Hammoud worries about chronic cases at his hospital, such as those on life support or kidney dialysis machines.

"I don't know what will happen to those patients if we have to shut down. They will be finished."