By Stephanie Nebehay
GENEVA (Reuters) - The United Nations wants to negotiate "humanitarian corridors" to let more aid into Libya where fighting in the east of the country has uprooted tens of thousands and hit food supplies, the U.N. said on Wednesday.
U.N. Humanitarian Coordinator for Libya Rashid Khalikov told a news conference Libyan authorities had indicated there was no major need for humanitarian aid, but discussions continued on how to best to support people affected by the conflict.
"There are various tools how we can assist people in the middle of conflict -- humanitarian corridors or days of tranquility," said Khalikov, who was in Libya from March 12-16.
"All this is on the table and we are ready to negotiate these things with parties to the conflict, all of whom have to adhere to principles of international humanitarian law."
The U.N. Office for the Coordination of Humanitarian Affairs (OCHA) said in a report released on Wednesday there was a high level of uncertainty over the current humanitarian situation in Libya, where Western air strikes began at the weekend.
"The situation of civilians in and around Ajdabiya, Misrata and other locations where active fighting continues remains of grave concern," it said.
At least 45 people, including civilians and children, were killed in fighting in Misrata on Monday and Tuesday, and a further 189 were injured, OCHA said. It quoted rebel forces as saying the situation in Misrata was critical, "as there is no water, fuel or electricity."
Khalikov said the U.N. had unconfirmed allegations Libyan government forces used human shields in the rebel-held western town of Misrata. This would be an "unacceptable" breach of international law, he stressed.
People in towns under attack may need supplies as services and food supply lines have been disrupted, according to the report produced by OCHA and other U.N. aid agencies.
"Medical needs in Libya are on the rise due to the recent fighting and are exacerbated by shortages of medical staff," it said.
"There are unconfirmed reports of an additional 80,000 internally displaced persons within Libya."
More than 335,600 people have fled Libya, mainly to Tunisia and Egypt, since the beginning of the crisis.
The U.N. pulled its international staff out of Libya in late February due to growing insecurity, but its food and refugee agencies have provided limited assistance in the east, according to Khalikov.
"The humanitarian situation is not only limited to the requirements in an emergency -- food aid, water supplies, medical supplies or shelter -- it's also protection of people who find themselves in the middle of cross-fire," he said.
Khalikov said the U.N. lacked sufficient information on the situation and he was not in a position to qualify it as a humanitarian crisis.
Western warplanes silenced Muammar Gaddafi's artillery and tanks besieging Misrata on Wednesday.
(Editing by Laura MacInnis and Sophie Hares)