Governments need to step up their efforts to combat corruption if they are to defeat extremists such as the "Islamic State of Iraq and the Levant" (ISIL), Transparency International warned Tuesday (February 21st).

In a 44-page report entitled, "The Big Spin", the watchdog said that corrupt practices in states such as Iraq, Libya and Nigeria are providing fertile ground for extremists, AFP reported.

"Corruption is the most powerful weapon in the armoury of violent extremism," it said.

The report said extremist groups drew on public anger at the abuse of power as a means to radicalise and recruit. They also use corrupt officials and their links to organised crime to facilitate financial and arms flows.

Corruption also hollows out state institutions that should keep extremist forces in check, the report said.

Airstrikes against ISIL in Iraq and Syria and similar attacks against extremists are "woefully insufficient" in building long-term stability, which requires accountable governments, it said.

"Radical movements like ISIL thrive when people lose all faith in those in power -- when officials profit from the misery of the many, when the police exploit rather than protect, and when economic opportunity is skewed in favour of the connected few," the report said.