KANDAHAR, Afghanistan — Nine NATO troops, including six Americans, were killed in Afghanistan over the weekend, according to military officials, a grim start to a month that follows the bloodiest 30-day period for foreign forces in the country since the war began nearly eight years ago.

Three American soldiers were killed Sunday in eastern Afghanistan when a bomb struck their patrol and insurgents attacked them with small-arms fire. The three soldiers died in the engagement, said Lt. Cmdr. Christine Sidenstricker, a U.S. military spokesperson in Kabul.

Two Canadian troops were killed Saturday when their patrol was struck by two bombs in volatile Zhari district, west of Kandahar Airfield, the main NATO base in southern Afghanistan, Brig. Gen. Jonathan Vance, commander of the Canada-led Task Force Kandahar, said Sunday.

The Canadian soldiers died the same day that three other U.S. troops were killed in a bomb explosion elsewhere in Kandahar province and a French soldier died in an attack north of Kabul.

The fatal attacks continue a bleak trend that began last month, when 75 troops — 43 of them Americans — were killed in Afghanistan, making July the deadliest month for foreign forces since the U.S.-led invasion in 2001.

More than half of those deaths were from bomb attacks, and nearly three-quarters of them have occurred in southern Afghanistan, where NATO-led forces have launched several large ongoing operations against Taliban insurgents, including massive offensives by U.S. Marines and British forces in Helmand province.

Despite the sharp rise in NATO deaths, Vance said troops were not failing in their mission.

“Yesterday alone, Task Force Kandahar conducted successful operations in securing suicide vests and seizing the contents of two major [bomb] factories that were obviously destined to find their way to Kandahar, maybe even to be used on election day,” he said.

As Canadian forces held a ceremony Sunday to send their two fallen soldiers home, four U.S. medevac helicopters landed at Kandahar Airfield and offloaded several wounded soldiers, a reminder that even as NATO troops mourned their losses, casualties continued in the field.

There are currently about 100,000 foreign soldiers in Afghanistan, including 66,000 Americans, and those forces have stepped up operations against the Taliban and other militants in advance of the Aug. 20 presidential election, only the second such vote in the country’s turbulent history.

Last Thursday, Taliban leaders urged Afghans to boycott the election, and called on its fighters to block roads to prevent people from voting, the Associated Press and other agencies reported.

Nearly 240 foreign soldiers have been killed in Afghanistan so far this year, according to www.icasualties.org, putting 2009 on track to be the bloodiest for international forces since the war began.

Last year, 294 international soldiers lost their lives in Afghanistan, according to the Web site, and violence has risen steadily every year since 2003.

The United States has lost at least 136 soldiers so far this year, followed by the United Kingdom with 54 deaths and Canada with 19 deaths, according to the icasualties.org site.

On Friday, the United Nations said that the number of civilians killed in the war has also escalated, rising by 24 percent during the first half of 2009 compared to the same period last year.

According to the U.N., at least 1,013 civilians died during the first six months of this year, compared to 818 during the same period in 2008. Taliban attacks were responsible for at least 595 of those deaths, the U.N. said.

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