One of the most sacred and treasured mosques for Iraq’s Shi’ite community has been badly damaged by blast. Armed men barged into the shrine in the town of Samarra this morning and placed bombs inside before running off.As news of the attack spread, thousands of demonstrators quickly took to the streets. Some carried out revenge attacks, ransacking at least nine mosques belonging to the minority Sunnis. The Iraqi Prime Minister, who is also a Shi’ite, has declared three days of mourning. Community leaders have urged those on the streets not to over-react. But the attack on the shrine comes during a week which has seen a surge in violence. More than twenty people were killed in a car bomb explosion in Baghdad yesterday. Many others were injured in the blast in a market place which spelt an end to a relative lull in violence over recent weeks.