It was the holiest day of the year. Hundreds and thousands of Shia Muslims gathered yesterday to celebrate Ashura, the festival commemorating the martyrdom of Imam Hussein Hussein in 680. The day had a special significance for Iraq's Shias, suppressed under the Sunni rule of Saddam Hussein but now exercising new religious freedoms. By last night, it had taken on an altogether darker significance after the murder of more than 170 Shia Muslims in Iraq alone, victims of multiple bomb attacks on Baghdad and the holy city of Karbala.

It was the bloodiest day in Iraq since the war on Saddam began, providing further evidence, if any were needed, that winning the peace is more fraught than winning the conflict. The targets of the Islamic Jihadi militants, who treat Iraq as the strategic battleground in a global war against the west, have shifted as coalition forces have become better at defending themselves and recruits to the Iraqi police force. It might be true that the militants and Saddam's loyal insurgents are running out of targets, but there is no comfort in that development when innocent men, women and children find themselves in the firing line.

Under international law, occupying forces are responsible for the safety of the population under their control. Coalition forces have a difficult balance to strike when protecting the public on sensitive religious occasions. Polish forces in charge in Karbala kept away from the Ashura festival yesterday as a mark of respect for the Shia Muslims, handing control on the ground to militia groups. There is no guarantee that there would have been fewer casualties if coalition forces had been responsible for security. A growing sense of resentment among Iraqis that the US army, main player in the coalition forces, is too busy protecting itself to worry about the civilians in its care will not be reversed unless more is done to protect Iraqi citizens.

Yesterday's attacks were aimed at destabilising Iraq by stoking communal violence between Shia and Sunni Muslims. The situation is tense but, if the dominant Shias react as they did to the bomb that killed 85 outside a mosque in Najaf, including a Shia spiritual leader last year, they will keep their eye on the political prize rather than be lured by the sectarian bait. They have much to gain from that approach. The US-led coalition ends its occupation on June 30 and an interim constitution - not based on Sharia law but enshrining Islam as one of several sources for legislation - will be in place until a new government is chosen in national elections, possibly by the end of this year. Shia Muslims will be in the majority and well-placed to shape a new constitution. The militants violently oppose both. Nor do they want their chosen cockpit for conflict eliminated by a transition to self-government,

stability and prosperity in Iraq. The best hope of that happening lies with holding the elections as soon as is feasible. Yesterday's events demonstrate that security at the polling booth will be critical.