BAGHDAD—U.S. deaths in Iraq fell in October to their lowest monthly level of the war, matching the record low of 13 fatalities suffered in July. Iraqi deaths fell to their lowest monthly levels of the year.

Eight of the 13 Americans died in combat, most of them in northern Iraq where al-Qaida and other Sunni insurgent groups remain active. The U.S. military suffered 25 deaths in September and 23 in August.

The sharp drop in American fatalities in Iraq reflects the overall security improvements across the country following the Sunni revolt against al-Qaida and the rout suffered by Shiite extremists in fighting last spring in Basra and Baghdad.

But the decline also points to a shift in tactics by extremist groups, which U.S. commanders say are now focusing their attacks on Iraqi soldiers and police that are doing much of the fighting.

—The Associated Press

Iraqi government figures showed at least 364 Iraqis killed in October — including police, soldiers, civilians and militants.

Despite the sharp decline, the Iraqi death toll serves as a reminder that this remains a dangerous, unstable country despite the security gains, which U.S. military commanders repeatedly warn are fragile and reversible.

U.S. commanders are also worried that security could worsen if the Iraqi parliament refuses to approve a new security agreement by the end of December, when the U.N. Security Council mandate under which the coalition operates in Iraq expires.

Without a new agreement or a new U.N. mandate, U.S. military operations would have to stop. Prime Minister Nouri al-Maliki’s government is pressing for changes in the draft agreement before submitting it to parliament.

Much of that concern focuses on Mosul, Iraq’s third largest city about 225 miles northwest of Baghdad. U.S. and Iraqi troops launched a new operation Oct. 15 to clear al-Qaida and other insurgent groups from the city.

Violence occurs almost daily in Mosul, although the U.S. military says attacks there are down by almost half since May.

Attacks and threats against Christians in Mosul prompted about 13,000 of them to flee the city in early October.

On Friday, a local official, Jawdat Ismaeel, said Christians were trickling back after police and soldiers increased patrols and checkpoints in Christian neighborhoods. He said that 35 Christian families, about 210 people, returned in the past week and that the exodus from the city had largely stopped.

The Iraqi government has offered each Christian family that returns 1 million Iraqi dinars — about $865 — although officials say the response so far has been lukewarm.

Also Friday, government spokesman Ali al-Dabbagh announced that Iraq and Iran have agreed to exchange bodies of soldiers killed during the 1980-88 Iran-Iraq war. He said the exchange — 200 Iraqi bodies for 41 Iranian — would take place Nov. 15 at a border post that he did not identify.

Hundreds of thousands of soldiers from both sides were killed or went missing during the war.

The International Committee of the Red Cross announced Oct. 16 that the two countries agreed on how to gather and share information about the missing and hand over any remains uncovered.