Up to 3,000 IS fighters in Libya: UN

The Islamic State group has between 2000 and 3000 fighters in Libya and has demonstrated its intention to control more territory in the strategically located North African country.

Some 110 Australians are now thought to be fighting in Iraq and Syria, mostly for Islamic State. Source: AAP

But it's only one player among multiple warring factions, United Nations experts said in a report on Tuesday.

The experts monitoring UN sanctions against al-Qaeda and spinoff groups said in the report to the UN Security Council that the Islamic State group is benefiting from its "appeal" and notoriety in Iraq and Syria and poses "an evident short and long-term threat in Libya".

The group's central command views Libya "as the 'best' opportunity to expand its so-called caliphate" from Syria and Iraq, the experts said.

The 24-page report cautioned, however, that the group "faces strong resistance from the population, as well as difficulties in building and maintaining local alliances" - and stressed that its threat "needs to be realistically assessed."

Nonetheless, the experts said there is concern at the spread of the Islamic State group in Libya, given the country's strategic location on the Mediterranean Sea and its use as a transit point in North Africa.

More territory would not only enable IS and al-Qaeda-linked groups to further influence ongoing conflicts in North Africa and the Sahel but give the extremists a new hub outside the Middle East, they said.

Eight independent experts were appointed by the Secretary-General to write the report, with expertise in counter-terrorism, financing of terrorism, arms embargoes, travel bans and related legal issues.

Oil-rich Libya slid into chaos following the 2011 toppling and killing of longtime dictator Muammar Gaddafi.

It is divided between an elected parliament and government based in the eastern port city of Tobruk and an Islamist militia-backed government in the capital Tripoli - with militants from IS and al-Qaeda also exploiting the chaos.

The United Nations has been pressing the rival governments to form a national unity government, so far unsuccessfully.

Several UN member states told the experts "that in total (IS) has no more than 2000-3000 fighters in Libya", with about 1,500 now in Sirte, the report said.