Five American troops were killed within 24 hours in southern Afghanistan, where Taliban militants have conducted an unrelenting campaign of bombings and attacks against US and NATO forces.
This has been the deadliest year of the war for international forces and the Obama administration is debating whether to add still more troops to the 21,000-strong influx that began pouring into the country over the summer.
The five deaths announced Friday occurred in three separate attacks the day before in the south, where US and NATO commanders have ramped up their operations to try to reverse Taliban gains.
The commander of US and NATO forces, Gen. Stanley McChrystal, told "60 Minutes" the strength of the militant group took him by surprise when he arrived this summer.
"I think that in some areas that the breadth of the violence, the geographic spread of violence, is a little more than I would have gathered," he said in the interview, to be broadcast on Sunday.
Four soldiers died in the same small district of southeastern Zabul province, three of them killed when their Stryker vehicle hit a bomb, and the fourth shot to death in an insurgent attack, said US military spokesman Lt. Robert Carr. The Stryker brigade arrived in Zabul as part of the summertime surge to try to secure the region ahead of Afghanistan's 20 August presidential election.
Meanwhile, a US Marine was fatally shot while on foot patrol in southwestern Nimroz province, said Captain Elizabeth Mathias, a military spokeswoman.
The US is on track to have 68,000 troops in Afghanistan by the end of 2009, but the Pentagon said McChrystal would ask this week for as many as 40,000 new forces. Some question the wisdom of sending more troops to support a government facing allegations of widespread fraud in last month's disputed vote.
About half of all Americans oppose increasing troop levels in Afghanistan, according to a poll released Friday. The New York Times/CBS News poll found that only 29 per cent of respondents believed the US should add troops in Afghanistan. The survey, conducted 19-23 September, had a margin of error of 3 percentage points.
In a report to the White House, McChrystal argued that military commanders need to be less preoccupied with protecting their troops and send them out into Afghan communities more. He acknowledged this "could expose military personnel and civilians to greater risk in the near term," but said the payoff in terms of forging ties with the Afghan people would be worth it.
"Accepting some risk in the short term will ultimately save lives in the long run," he wrote.
The light-armored Stryker vehicles were sent to Afghanistan as part of a plan to take over a large swathe of the south. The idea behind the vehicles is that they can deploy quickly over large distances, exercising control over a much larger area than can be held by foot soldiers. However, they are more vulnerable to roadside bombs than more heavily armored vehicles.
Bombs planted in roads, fields and near bases now account for the majority of U.S. and NATO casualties and have proven especially dangerous in the south. With the five deaths, a total of 34 U.S. forces have died in Afghanistan in September. August, which was the deadliest month of the war for American troops, saw 51 deaths.