Insurgents unleashed a wave of five car bombings across the capital Wednesday, killing about a dozen people, despite stepped-up U.S. and Iraqi measures to protect this month's elections. North of Baghdad, insurgents killed a British security officer and kidnapped a Japanese engineer, officials said. Gunmen fired on the Baghdad office of a major Kurdish party and two senior officials escaped assassination in separate attacks in the north. The U.S. military put the death toll from the day's Baghdad bombings at 26, saying the number was based on initial reports at the scene. Iraqi officials gave a lower toll _ 12 people killed in the bombings and one at the Kurdish office. Sunni Muslim insurgents have threatened to disrupt the elections, and the five car bombings _ four within a span of 90 minutes _ underscored the grave threat facing Iraqis at this watershed in their history. U.S. and Iraqi forces have stepped up raids and arrests in Baghdad, Mosul and other troublespots as the elections approach.