Reporting from Baghdad - Suicide bombers killed at least 79 people today in two attacks in Iraq, reviving fears that Sunni extremists are gearing up for a new campaign of violence just as U.S. forces are preparing to pull back from the nation's cities. There were no immediate indications that the bombings in Baghdad and nearby Diyala province were coordinated. But they vividly demonstrated that militant groups are still capable of staging attacks that cause mass casualties, as they did in the darkest days of the country's 2006-07 sectarian war.