The situation of thousands of people trapped by war in south Lebanon is unacceptable and Israel must do more to spare civilians, the International Committee of the Red Cross (ICRC) said on Friday.

"We today find the situation for civilians who are trapped unacceptable," said Pierre Kraehenbuehl, the ICRC's director of operations.

"International humanitarian law sets out clear rules and the parties in this context are aware of their obligations," Kraehenbuehl told reporters at a press conference in Geneva.

He said much more had to be done by Israeli forces to ensure the respect of international humanitarian law and to protect and spare civilians in the conduct of military operations.

The ICRC on Monday also appealed for 100 million Swiss francs (some 80 million U.S. dollars) to sharply step up the humanitarian work it was carrying out for the victims of the armed conflict in south Lebanon.

In south Lebanon, particularly the villages along the border with Israel, the effects of military operations are rapidly making life unbearably dangerous for the remaining civilians trapped by the fighting, it said.

In addition, resources and access to water and basic services are very limited. Medical evacuations and aid operations are fraught with difficulty and cannot meet the needs.

"In southern Lebanon, the number one issue today is to ensure the safety of civilians and securing safe access for those engaged in medical and other humanitarian activities," Kraehenbuehl said.

"At the same time, the damage to civilian infrastructure and the country's economy, coupled with the large-scale displacement of civilians, requires an emergency response that is likely to extend into next year," he added.

Across Lebanon, the funds requested will serve to expand health programs and support medical facilities serving 650,000 people, as well as to help treat up to 5,000 war-wounded.