Thousands of people have marched through the northern Iraqi city of Mosul to protest against Sunday's attack on one of the Baghdad's largest churches. Muslims mixed with Christians for the demonstration and to appeal jointly to the government to step up security. The third major attack in nearly as many days appears to show that a weakened but stubborn insurgency has a greater capacity to carry out large-scale strikes than U.S. and Iraqi officials have acknowledged. Iraqi officials say 52 people were killed and 67 others hurt in the raid on the Assyrian Catholic church mass, making it the bloodiest attack on Iraq's Christian minority since the start of the US-led invasion in 2003.