How Iraq's war has turned friendship between families into sectarian hatred

They are two Iraqi families, one Shia, the other Sunni, who once lived in what were called "mixed" neighbourhoods. Now they are among the 2 million internal refugees in the country, a vast and desperate pool of the dispossessed whose numbers have risen massively along with US troop "surge" operations.

The forced migration, called "a human tragedy unprecedented in the country's history" in the latest Iraqi Red Crescent report, has uprooted communities from homes they have occupied for decades. In Baghdad, the focus of US military action, there are a million displaced people in a population of four million.

Another two million people, according to UN estimates, have fled abroad. Amnesty International, in a report released today, identifies Britain as forcibly returning more Iraqi refugees than any other country in Europe.

But it is the internal diaspora that is causing acute problems in this fractured society, with numbers rising by 71 per cent in just one month, according to the Red Crescent. The Independent has spoken to two families, the al-Rawis and the al-Amirys, who had been forced to flee their homes. In both cases the horrors they endured have turned tolerance and friendship across the religious divide into sectarian anger and hatred.

Um Samir al-Rawi is now living with her two daughters, Saba, 33, and 28-year-old Hiba, in a dark and dingy house in Khadra, a Sunni neighbourhood where they had taken refuge after being driven out of their home in the previously mixed Jihad district. Mrs al-Rawi's husband died in 2004, and their son, Samir, is now in exile in Syria after being hunted by the Mehdi Army Shia militia, which had accused him of being an insurgent.

"I asked Samir to stay at a friend's house in Mansour, he is the only man left in the family and we could not afford to lose him," said Mrs al-Rawi, 69. "It was very fortunate that he left, otherwise he would have been killed. The Mehdi Army were shouting that all Sunnis were terrorists and deserved to die. They killed one of our neighbours, Abu Bakr. They shot him in cold blood in front of his home. He had refused to leave his house. We were also told that he was killed because of his son's name."

The Shia militias are said to have a particular hatred of Sunni names, such as Bakr and Omar. That people can die because of their name may seem far-fetched, but not in Baghdad. Last year morgue attendants found a dozen bodies, killed in different locations, gathered in a pile. The identification papers, left on the chests of the corpses, all bore the name Omar.

Mrs al-Rawi continued: "We had to leave. It was terrible, all we had time to take were some of our clothes, documents and our identification cards. We were frightened, we had no idea where to go. The last thing we did was put the holy Koran in the living room and asked God to protect us and our home."

The family stayed at a school which had been turned into a centre for refugees. But the sparse communal facilities for several hundred people, many of them sick, became unbearable and the al-Rawis pooled their meagre resources to rent a house.

Mrs al-Rawi said their former neighbour told them that since their departure, "the militia had broken the locks of our house and four Shia families are living there now. I feel very angry with the Shias, I cannot forgive them. The house was built by my father and now we have lost everything. Here we have just a few pieces of furniture and are prisoners in this neighbourhood."

Just a few miles away, across a dried-up tributary of the Tigris, Assem al-Amiry, another refugee, has journeyed the other way, from a mixed area to what is now a predominantly Shia one.

The al-Amirys – Assem, 41, his wife Siham, 39, daughter Hadeel, 10, and son Haitham, five – used to live in Ghazaliya, where life became particularly dangerous after the destruction of the golden dome of the shrine at Samarra last year.

"We had al-Qa'ida attacking our district all the time," Mr al-Amiry said. "They began killing Shias, calling us kafirs, saying we were unclean and they will dispose of us. The government did nothing to protect us. Some of my neighbours left, others were killed, but I refused to go, it was my home. Then one morning my daughter found an envelope on the doorstep with an AK-47 bullet and a note telling us that we had 48 hours to get out, or we would all be killed."

Mr al-Amiry moved his family to al-Huriya where they have rented a house for $120 a month. He has started to work as a money changer. "I got a telephone call from a Sunni neighbour who told me the insurgents had looted our home and then burnt it along with the other Shia houses," he said.

Hadeel, aged 10, was confused by it all. "What is Shia? What is Sunni?" she said. "I do not understand. I used to play with my friends and we used to go to school together. I miss them and I think they must miss me."