Inadequate security permit militia groups in the south -- allegedly backed by neighboring countries -- to loot the region's riches, particularly along the borders, the Alsumaria Iraqi satellite network reported Monday.

A U.S. report estimated oil smugglers pocketed yearly revenues of nearly $4 billion, equal to some developing states' budgets, the network reported.

Observers said recent clashes between security forces and al-Yamani groups in Basra and Nasiriyah were attempts to demonstrate that Iraqis weren't capable of taking over their country's security, among other things.

Evidence of Iran's involvement include Iranian-made grenades, explosives and anti-armor missiles, Alsumaria reported. Also, Tehran was accused of being behind the assassination of two southern governors last August.