It took eight years for Nur Muhammad, 35, finally to fall pregnant with the child she desperately wanted. Last week, Ali, her pride and joy, became the youngest victim of the upswing in violence.

The four-month-old baby boy fell ill last Monday with a fever, the day fighting broke out in Basra, the second-biggest oil city of Iraq. The street where the family lives became a battlefield, imprisoning them in their home, unable to get help.

'The disease spread so fast. My husband tried to leave our home to look for help but he was shot in his leg in front of our house,' Muhammad said. 'My only child was seriously sick and I also had to look after my injured husband. I was forced to use a knife sterilised with a lighter to take the bullet from his leg.'

No one was able to reach the house with medicine or food until Friday afternoon. Ali had died in the morning. 'It took me a few hours to realise my son had become an angel. He was shining and had a smile on his face,' she said. 'I waited all my life to have my baby and now a ridiculous political fight for supremacy took him away from me.'

Muhammad, tears streaming down her hollow cheeks, was in deep shock. 'I don't have a reason to live anymore. My husband threatened to divorce me if I didn't give him a child and now I doubt he will stay married to me now that Ali has been taken.'

Since Monday, when Basra erupted in violent clashes between the Mahdi army of Shia leader Moqtada al-Sadr and the Iraqi government, hundreds of families have been unable to leave their homes to look for food, water, health care, and oil for generators.

Officials report that more than 160 have been killed and at least 400 injured in the last five days.

'By the time many of the injured reach the hospital, they cannot be saved. The difficulties in getting to medical centres also costs lives. Even medical staff can't get to work as the situation on street remains critical,' said a clinician at Basra Main Hospital, who asked to remain anonymous. 'We are lacking medical supplies and parts of the hospitals have no electricity. Pregnant women are risking home deliveries.'

Khalid Jalal, 36, a pharmacist and father of three, said his family had been without food and electricity since Tuesday. He said: 'My children are starving and masked militants have prohibited us from leaving our home. I cannot stand seeing my kids crying for food and forced to drink unclean water because militants believe they are God's soldiers.

'God doesn't want a human being to suffer - but that is what the fighters and the government are giving us, rather than the promised US democracy. They are looking for supremacy while innocent people die for no reason,' he said. 'I was happy when the British troops left Basra, but now I urge them to come back to save the lives of my children.'

The International Committee of Red Cross is concerned about the humanitarian impact of fighting in Basra and Baghdad and says many families are now reduced to bringing their own generators to Baghdad hospitals to ensure they have sufficient power supplies.

Schools, universities government offices and shops are closed in Basra and many neighbourhoods of Baghdad. Streets are empty and few faces can be seen near windows.

In the Shia mosques of Baghdad, Basra, Hilla, Nasiriyah and other southern provinces, religious leaders call for support and criticise the government's attitude towards Sadr followers. They accuse the Shia Prime Minister, Nouri al-Maliki, of being a betrayer and an American devotee.

There are food and medicine stockpiles in a number of warehouses in Basra but so far it has been impossible to distribute them. Aid delivery has stopped inside the city until security improves. A curfew in Basra was eased on Friday to allow movement around the city from 6am to 6pm but, in many districts, the actions of militants have kept them indoors.

British military spokesman Major Tom Holloway said coalition forces were providing air support and helpinto refuel Iraqi helicopters and transport planes. 'The British military is providing air power over Basra as the Iraqi air force doesn't have fast jets yet,' Holloway said. 'We are closely helping to provide military support to bring peace back to Basra.'

Funerals have been seen taking places in areas of Baghdad and Basra where clashes have diminished; anger and desperation are etched on the mourners' faces.

'My uncle and cousin were killed in an air strike in Sadr City on Friday. The US says it is just attacking militants so how can they explain how two innocent people, who were hard workers and far from politics and social issues, are now dead?' said Assad Hassan Alawi, 24, a student in Sadr City.

'They left women and children without anyone to bring them food. Maybe they are going to be the next victims - not from an air strike, but from hunger caused by the unfair Iraq invasion,' he said. 'I'm against the war, the fight for power and any religious leader who, instead of spreading the true Islamic peace, multiplies violence and death.'