By James Reynolds
BBC News, Baghdad
For some of Iraq's most terrified people, there is a new home - a ragged camp in the north of Baghdad.
Some families have been given just 24 hours to leave their homes
Shia families have come here to escape from gangs of armed Sunnis.
A squad of police officers stands at a distance, watching my colleagues and me as we begin talking to people.
One man tells us we are the first outsiders here - but it is impossible to tell for sure.
Inside one of the tents, we meet Naima. She fled with her five children after her family received threats from Sunnis. And she is still scared.
When we ask her if we can take some pictures she pulls a veil across her face to avoid being identified.
"We were threatened because we are Shias," she says.
"They posted death threats. They call on mobile phones and say: 'You think you've got away? We'll go after you'."
Outside the tent, another woman comes up to us.
She holds up her three-month-old baby, Karar, who is sick.
She says that she came here after her husband was threatened.
"They posted a threat: 'You have to leave within 24 hours or your house will be blown up'," she says.
It is difficult to know for sure how many people have been displaced in Iraq.
Not everyone finds shelter in official camps. Many people are too afraid to talk. And there are many places that we - as Western journalists - simply cannot get to.
The Iraqi Red Crescent says that almost 100,000 people - Shias and Sunnis - have had to flee in fear in what may be an ordered campaign.
"The problem is big and it's growing exponentially," says Dr Said Hakki, the organisation's president.
The exodus accelerated after a Shia mosque was bombed in February
"The Iraqi Red Crescent feels that this is an organised issue. Somebody is behind this who is highly organised."
"Are the authorities doing enough ?" I ask.
"They're doing their best, that I can see. But whether that's enough or not is a different question."
Sunnis are victims as well as Shias.
I meet a woman and her son in a park in Baghdad.
We ask an armed guard to come along with us for everyone's safety.
We agree not to reveal her name. She hides her face behind a veil - so that all you can see are her bright green eyes.
She tells me that she and her son fled after Shia militiamen stormed her home and began killing members of her family.
"They handcuffed one brother, crushed his head, and pulled out his tongue," she says.
"His mother was made to watch. They cut off his ears and nose and shot him. Then the next brother was taken outside and shot. And the last brother was taken outside.
"The militia ordered people to gather round. They tortured and executed him. Afterwards they said 'That is the fate of every Sunni'."
For now, the woman and her son will stay in hiding, with relatives in a Sunni neighbourhood.
She is not sure when it will be safe to return home. Like the Shias in the ragged tent camp, she now lives in fear of her fellow citizens.