BAGHDAD — The Shiite militia's threat came in a typed letter tossed at Mohammed Abdul-Wahab's door: "Leave this house within 48 hours or you will face death."

The Sunni government worker did just that — fleeing his ancestral home in a mostly Shiite area of Baghdad with his wife and 2-year-old son.

Now, struggling to pay rent higher than his salary, Abdul-Wahab is among the nearly 2.3 million people the Iraqi Red Crescent says have been driven from their neighborhoods as Iraq is increasingly carved up along sectarian lines.

The number of internally displaced people has swelled in Iraq since the beginning of 2007, when the group counted less than half a million.

A new report issued Monday by the Iraqi Red Crescent shows that such people now outnumber Iraqis who have fled the country altogether for refuge in neighboring states like Syria and Jordan.

The rise came despite a sharp drop in bombings, shootings and other violence more than four months after the U.S. completed a 30,000-strong force buildup here. American and Iraqi death tolls have also fallen dramatically.

At least 17 Iraqis were killed or found dead Monday, police and morgue officials said, including a councilman gunned down in a neighborhood next to his own in western Baghdad.

On average, at least 56 Iraqis — civilians and security forces — have died each day so far in 2007, according to figures compiled by The Associated Press.

Deadly rivalries have forced Shiite and Sunni Muslims to flee once diverse neighborhoods across Iraq's capital, leaving the city with clear boundaries between sects. More than 60 percent of those forced to flee were in Baghdad, the report said.

"I didn't harm anybody, and I don't know why I was displaced and my house was taken by another family," said 28-year-old Abdul-Wahab, who fled his Jihad neighborhood last December.

His house had been in the family for generations. Now, coupled with his wife's income as a teacher, Abdul-Wahab's meager government salary — $120 per month — is just enough to rent another house in nearby Amariyah, a Sunni enclave. They have almost no money left for food.

"The two salaries are not enough. We have to buy milk for our baby," Abdul-Wahab said. "We filled out an application form for displaced people at the immigration ministry, for extra income, but so far we have received nothing."

In some places like Shiite-dominated Hurriyah in northwest Baghdad, fighting has subsided because there are literally no more Sunnis left to kill.

The scramble for safety in segregated enclaves was thought to have eased after anti-American Shiite cleric Muqtada al-Sadr called a formal cease-fire in August. His militia, the Mahdi Army, was blamed for dozens of bodies turning up on Baghdad's streets each day — apparent victims of sectarian murders.

But while the daily body count has dropped dramatically — three corpses were found Monday in Baghdad — the Red Crescent said the number of residents displaced from their homes rose 16 percent in the month after al-Sadr's cease-fire.

About 83 percent of the country's displaced people are women and children under the age of 12, the organization reported. And many are not able to find permanent housing like Abdul-Wahab was.

"Children do not attend schools and are being sheltered in tents, abandoned government buildings with no water or electricity, mosques, churches, or with relatives," the report said. "In addition to their plight as being displaced, the majority suffer from disease, poverty and malnutrition."

Four and a half years after the U.S.-led invasion, the Iraqi government struggles to provide basic services — water, electricity and access to schools and medical care — to citizens across the country. Much of Iraq, especially the capital, is beset by violence, crumbling infrastructure and rampant crime, and most humanitarian groups are unable to reach victims who need help.

Some 2.3 million Iraqis have been driven from their homes but remain inside the country's borders, according to the Red Crescent's most recent figures, through Sept. 30.

According to the U.N. High Commissioner for Refugees, some 2 million Iraqis have fled their country. Of these, 1.2 million are in Syria, 750,000 in Jordan, 100,000 in Egypt, 54,000 in Iran, 40,000 in Lebanon, 10,000 in Turkey and 200,000 in various Persian Gulf countries.

The figures in Monday's Red Crescent report were tabulated by Red Crescent coordinators and volunteers in all 18 Iraqi provinces. The group says it has 5,000 employees and 95,000 volunteers working at 365 offices around the country.