KABUL - Afghan civilians are increasingly being squeezed between dueling sides as armed groups have multiplied and fighting has spread in recent months, the head of the International Committee of the Red Cross in Afghanistan said Wednesday.

As the war affects more areas of the country, a growing number of Afghans have been caught in crossfire and thousands have fled their home towns, Reto Stocker, the head of the ICRC here, said during a news conference in Kabul.

"We are entering a new, rather murky phase in the conflict in which the proliferation of armed groups threatens the ability of humanitarian organizations to reach the people who need their help," Stocker said. "The conflict is now in its 10th year. It is spreading. There is no end in sight."

The assessment was unusually bleak and blunt for an organization that tends to be circumspect in public. ICRC officials in Afghanistan have a deep and nuanced understanding of the conflict because they have open lines of communication with all major armed groups, including the Taliban.

The grim appraisal comes as U.S. military officials are arguing at a White House review of the Afghanistan war strategy that they have made progress in curbing the Taliban's momentum. President Obama is to speak about the review's assessment Thursday.

Stocker said the news conference was held as an "expression of us being extremely concerned about yet another year of fighting."

The early weeks of winter have been unusually deadly this year following an influx of U.S. troops into Taliban strongholds in southern and northern Afghanistan.

Violence tends to ebb here when freezing temperatures make fighting more arduous. But Taliban members have fought back vigorously against the latest offensive, attacking NATO troops with powerful roadside bombs, grenades and small-arms fire.

On Wednesday, NATO said three Afghan children were killed and nine civilians were seriously wounded in a roadside bombing in the southern province of Kandahar, a Taliban stronghold where the U.S. military is trying to flush out the group's fighters and restore Afghan government control.

A day earlier, in neighboring Helmand province, a NATO airstrike mistakenly killed an Afghan civilian and wounded two children, military officials said in a statement.

"We are here to protect the Afghan people, and in this case we may have failed," Air Force Brig. Gen. Timothy Zadalis said.

Stocker said an unprecedented number of Afghans are being asked to choose sides as the fight between NATO-backed Afghan forces and groups opposed to the presence of foreign troops has spread to more areas.

"Ten percent are pro-government, 10 percent are pro-Taliban," Stocker said. "Eighty percent sit on the fence. Many people see fleeing as their only solution."

Stocker said that in 2010, ICRC officials helped 140,000 Afghans who had been displaced from their homes - a 25 percent increase over the number the group helped last year.

In the ICRC-run Mirwais Hospital in Kandahar, doctors have treated 2,650 war victims this year, about 400 more than in 2009, he said.

"Afghans are tough," Stocker said. "They have learned to be tough. But the simple fear of being caught in between is really pushing people to the brink."