By Jill McGivering
The attack on the Buratha Mosque in Baghdad on Friday has left many Iraqis shocked and in fear.
The mosque was packed with worshippers at the time of the blast
This was a vicious attack on one of Baghdad's biggest Shia mosques.
It seemed carefully timed to cause a large number of casualties, targeting hundreds of worshippers as they poured out of the complex after Friday prayers.
It is a bitter blow to unity at a sensitive time, just as Iraq's politicians are struggling to bridge the sectarian divide and find the unity they need to form a new government.
It is a further blow, too, to public confidence, adding to the daily fear faced by many Iraqis of being caught up in the continuing violence.
For three years since the invasion of Iraq, many in the most troubled areas of the country have tried to avoid public places as much as possible, anxious about bombings or shootings, as well as a general increase in crime.
This surge in attacks on mosques in recent months has compounded anxiety about gathering for worship, too.
Some Iraqis are wondering whether they should now pray at home
Attendance at some large mosques is said to have fallen.
One man told the BBC his family now urged him to pray at home instead.
It is the latest in a series of constraints for Iraqis in the worst-affected parts of the country, constraints which, after three years, have almost become a new way of life.
Many people refer to the militant violence now simply as "the events", a way perhaps of making it possible to live with the constant threat of attacks.
Social activities are limited.
A recent curfew means most people must be at home by eight o'clock in the evening.
Fear of kidnapping and other crime has led to extra vigilance in monitoring the movements of children and women.
Om Hamada, a mother of four living in central Baghdad, said she rarely saw her relatives now.
"We cannot visit anyone, friends or family," she told the BBC during a day of special coverage on life in Iraq.
"We only keep in touch by the phone. I have many family errands to do, visits and so on, I can't. Why?" she added.
"Because I am scared, of the road, of the explosions, of the Americans who just shoot at anyone, the national guards, the gangs."
Um Mostafa, a hairdresser in Baghdad, said she had not allowed her 15-year old daughter go to school for the last two years because of the fear of kidnapping and assault.
Her young son attends primary school but she said: "One day I allow him to go to school and then he stays home the next day."
Services such as healthcare are being overstretched
Basic services are increasingly strained.
Hospitals are struggling to cope with the impact of victims of the violence - some needing lengthy rehabilitation - with their own resources depleted.
That is with a shortage of health professionals as many flee the country.
"The country is bleeding," said one doctor, Dr Salam Ismael. "Three thousand doctors, as an estimate, left Iraq in the last two years," he added.
"Two hundred and fifty have been kidnapped and 60 have been killed inside Iraq."
And despite efforts to rebuild, many people still struggle with the daily problems of damaged basic infrastructure: a limited electricity supply at home and at work, problems with the domestic water supply and a lack of fuel for generators, one of the few available alternatives.