UNITED NATIONS - Aid agencies have prepared food and medical supplies on the outskirts of Libyan city Sirte, but fighting between forces loyal to the Libyan National Transitional Council and pro-Muammar Gaddafi fighters has limited humanitarian access, the UN humanitarian arm said here Tuesday.

As Libyan government forces claimed a new military advance into Libyan strongman Moammar Gadhafi's hometown last Saturday, Some 6, 000 people have been displaced from the city and humanitarian access has been limited due to fierce fighting, the UN Office for the Coordination of Humanitarian Affairs (OCHA) reported.

In an update message provided on Tuesday, the Office said that there are "substantial requests for food assistance, especially from Sirte, Bani Walid and Sabha," as pockets of fighting still continue in these northern cities.

"Although exact numbers are still unclear, the numbers of people needing food aid may be higher than previously anticipate," said OCHA.

OCHA estimated that there are between 100,000 and 150,000 internally displaced persons (IDPs) in the country. Serious protection concerns remain for about 50,000 IDPs from minority groups due to direct threats to their personal security as well as social discrimination.

Relief workers are also concerned about the situation of third- country nationals, including migrants, refugees and asylum-seekers, who have become more vulnerable to human rights violations since the outbreak of the conflict, the Office added.