US military and intelligence officials say the size and resources of Iraq's insurgency are much greater than originally thought.
Pentagon officials told reporters this week that foreign and domestic fighters in Iraq number between 8,000 and 12,000 people, and as many as 20,000 when active sympathizers are added. This contrasts sharply with earlier estimates of about 7,000 insurgents.
American officials say there are as many as 50 militant cells across Iraq funded by an underground financial network of former Ba'ath Party leaders and Saddam Hussein's relatives.
The officials also believe the cells are receiving a significant amount of money from wealthy Saudi individuals and Islamic charities who funnel money through Syria.
Since Ramadan began last week, officials say daily attacks have increased 25 percent. They say only a small number are carried out by foreign terrorists like Abu Musab al-Zarqawi, but that those tend to be more deadly.