(VOVworld) - The IS jihadist group has significantly expanded its control over Libya, fueling demand by the country's warring parties for more arms to confront the threat.

Libyans inspect the site of an IS truck bombing on a police school in Zliten in January (AFP)

The panel of experts on the UN sanctions committee made the warning in its annual report released on Thursday. According to the report submitted to the Security Council, there are 6,000 IS militants in Libya, doubling or even tripling the estimates for 2015.

IS has successfully recruited young men from local tribes, offering them protection and benefits but it has also enlisted military officers who had served the former leader Muammar Gaddafi.

Many of the gunmen are foreign fighters who have travelled through Sudan, Turkey, and Tunisia to join IS and are mainly stationed in Sirte, the IS stronghold.