Foreigners flock to fight for Isis cause

Australian teenager Abdullah Elmir appears in a jihadist video.

About 1000 foreign fighters are pouring into Syria and Iraq every month in a global movement of jihadists that exceeds even that into Afghanistan in the 1980s, assessments from the United Nations and US intelligence show.

As the Islamic State (Isis) continues to make advances despite more than 600 coalition air strikes, the total number of foreign fighters is now thought to have passed 15,000, according to a UN Security Council estimate.

Although most fighters still come from the Middle East and North Africa, more than 2000 have come from European countries - including 500 from Britain since 2011 - carrying passports that would allow them to return freely to their home countries.

"Numbers since 2010 are now many times the size of the cumulative numbers of foreign terrorist fighters between 1990 and 2010 - and are growing," according to advance excerpts of the report obtained by the Guardian.

"There are instances of foreign terrorist fighters from France, the Russian Federation and the United Kingdom of Great Britain and Northern Ireland operating together."

The UN figures tally with American assessments that show a steady stream of fighters continuing to flow into the region. Estimates in March said there were 7000 fighters, in July 12,000 and last month 15,000.

European governments including Britain have taken measures to try to stem the flow of fighters into Isis' ranks as the organisation continues to grow. It is as yet unclear how effective those measures will be.

"It could take some time for the dampening effect of these measures to start showing up in the foreign-fighter intelligence estimates," US intelligence officials told the Washington Post.

It has been estimated that strikes in Syria alone have killed about 460 Isis jihadists, but the organisation continues to grow, its finances swelled by a reported 625,000 ($1.2millon) a day in oil smuggling revenues alone.

Bolstering its treasury is up to US$45million ($57million) from kidnapping for ransom, the UN report found.

The latest estimates came as US jets continued to pound the Syrian town of Kobane, which lies at the Turkish border and has been under siege for the past 40 days by an Isis offensive.

The bombardment came in preparation for an influx of 150 heavily armed Kurdish Peshmerga reinforcements into Kobane from the Turkish side of the border, near the town of Suruc.

They are following an estimated 200 fighters from the Free Syrian Army who entered Kobane this week.

Separately the Britain-based Syrian Observatory for Human Rights said that preliminary information indicated that at least 21 Isis members were killed in coalition air strikes around Kobane, including a Danish jihadist.