Six bombs exploded killing 19 people and wounding 66 in busy markets and streets across Baghdad Wednesday, police and medical sources said. The simultaneous explosions were the latest in a series of blasts and assaults to mark the most extreme wave of violence to hit Iraq in at least five years. Iraq's Shiite-led government has blamed Sunni Muslim insurgents with links to al-Qaida for the increased bomb attacks in the country, which have mainly targeted Shiite citizens. Four people were killed and 14 wounded in one of the worst attacks Wednesday when a roadside bomb exploded near a crowded market.