The top U.S. commander in Iraq says al-Qaida terrorists and Shi'ite death squads are primarily responsible for the wave of sectarian violence in Baghdad.
General George Casey spoke after meeting with U.S. Defense Secretary Donald Rumsfeld.
Rumsfeld is in Baghdad in an unannounced visit. After meetings with Iraqi and U.S. officials, Rumsfeld said the political process is critical to security in Iraq. He said Iraqi Prime Minister Nouri al-Maliki's reconciliation plan could help bring an end to sectarian violence sweeping Baghdad.
Rumsfeld said earlier today that the number of U.S. and Iraqi troops in the capital has been increased from 40,000 to 55,000.
Also Wednesday, a suicide bomber killed seven people in a restaurant in eastern Baghdad. And Iraqi security officials say they found the bodies of 20 bus drivers kidnapped earlier today north of the capital.
Iraqi Prime Minister Maliki has appealed to the country's Shi'ites and Sunnis to end sectarian strife and "unite as brothers" in the fight against terrorism.
Some information for this report was provided by AP.