The United Nations refugee agency said it is receiving reports of increased displacement in Libya, while the numbers of people fleeing the North African nation amid what Secretary-General Ban Ki-moon called "the brutal campaign of violence by the Libyan regime against its own people" have remained steady.

Non-governmental partners working with the UN High Commissioner for Refugees (UNHCR) estimate that up to 20,000 people have been taking refuge in the small town of Al Butwen, east of Ajdabiya for over two weeks, while some 5,000 people are displaced in the coastal town of Derna.

The agency has sent two convoys with medical supplies to the rebel-held city of Benghazi through the Egyptian Red Crescent and the Libyan Red Crescent, as well as thousands of blankets, sleeping mats and other relief items.

However, UNHCR does not currently have access to deliver humanitarian aid into other parts of Libya, spokesperson Melissa Fleming told a news conference in Geneva.

Colonel Muammar Al-Qadhafi has waged a fierce military crackdown in response to the protests that erupted in Libya last month as part of a wider movement calling for reform across North Africa and the Middle East.

As of 23 March, more than 350,000 people have fled the violence in Libya, with most of them going to neighbouring Egypt and Tunisia, said UNHCR. It added that the numbers of those fleeing have remained steady over the past few days.

Yesterday Mr. Ban reported to the Security Council that although the Libyan authorities have repeatedly claimed to have instituted a ceasefire, there has been no evidence of that.

"To the contrary, fierce battles have continued in or around the cities of Ajdabiya, Misratah and Zitan, among others. In short, there is no evidence that Libyan authorities have taken steps to carry out their obligations under Resolutions 1970 or 1973," he said, referring to last week's resolution and an earlier one calling for a ceasefire and full protection of civilians.

In a related development, the head of the UN Educational, Scientific and Cultural Organization (UNESCO), Irina Bokova, today condemned the killing of Libyan journalist Mohammed al-Nabbous on 19 March and called for all journalists detained in the country to be freed.

According to the International Press Institute, the 28-year-old founder of online channel Libya Al-Hurra, or Free Libya, was killed by snipers in Benghazi during an attack on the city by pro-Qadhafi forces.

"His tragic death, along with numerous reports of journalists being detained in the country, indicates just how dangerous Libya has become for media workers," Ms. Bokova stated in a news release.

"In keeping with the Geneva Conventions to which Libya is a State party, it is essential that all those in positions of power in the country respect the right of journalists to do their work unhindered," she added.

Mr. al-Nabbous is the second journalist to be killed in Libya within the past two weeks, said UNESCO. Ali Hassan al-Jaber, a cameraman with Al Jazeera, was killed in an apparent ambush last week.