A group of American soldiers and Afghan officials had been traveling through the world's largest opium poppy producing region — the southern province of Helmand — when they discovered the roadside bomb and tried to defuse it, said Kamal Uddin, Helmand's deputy provincial police chief.
Helmand is a stronghold of Taliban militants, who control wide swaths of territory in the province. Helmand has long been the domain of British forces in the 40-nation fight against the Taliban, but the U.S. is expected to send thousands of troops there this year to help battle a militant movement that has grown in strength in the last three years.
The top NATO commander said Sunday that operations to attack drug lords and labs in Afghanistan will begin within the next several days in an effort to strike at a key income source for the Taliban.
"Activities and actions will occur soon that will be helpful," Gen. John Craddock told reporters at a security conference in Munich. "We've got to get started."
Late last year, NATO defense ministers authorized troops in Afghanistan to launch the drug attacks, but there had been questions about whether allies would be willing to follow through. Money from Afghanistan's booming illicit drug trade has been blamed for pumping up to $100 million a year into the coffers of resurgent Taliban fighters.
In the capital, Kabul, a U.S. general said Russia's granting of transit rights to non-lethal U.S. military supplies bound for Afghanistan will make it harder for militants to attack the American supply line.
Brig. Gen. James C. McConville, deputy commanding general in charge of support for U.S. troops in eastern Afghanistan, said Russia's announcement Saturday "gives us another opportunity" to bring supplies into the country.
"As agreements are made, of course that presents more challenges to those who are trying to stop these supplies that are coming into the country," he told a news conference.
The supply line into Afghanistan has come under increasing threat in the last several months. Some 75 percent of U.S. supplies comes through Pakistan, but militants have stepped up attacks on trucks bringing in food and fuel. The latest attack was on a bridge in Pakistan's mountainous Khyber Pass, temporarily halting traffic.
McConville insisted that the U.S. has not seen any effect on supplies from the attacks.
The Russian decision follows Kyrgyzstan's announcement last week that it will close the Manas air base used by the U.S. military for moving troops and supplies into Afghanistan.
U.S. officials suspect Russia was behind the decision, having long been irritated by the U.S presence in central Asia.
Any new transit routes through Russia are unlikely to make up for the loss of Manas, home to tanker planes that refuel warplanes flying over Afghanistan as well as airlifts and medical evacuation operations.
The Kremlin last year signed a framework deal with NATO for transit of non-lethal cargo for coalition forces in Afghanistan and has allowed some alliance members, including Germany, France and Spain, to move supplies across its territory.
Ground routes through Russia would likely cross into Kazakhstan and then Uzbekistan before entering northern Afghanistan.
In other violence, Afghanistan's intelligence service said Afghan villagers on Sunday executed an attacker who killed a member of Nangarhar's provincial council on Saturday. A spokesman for the National Directorate of Security said the villagers tied the attacker to a tree and shot him.
"We welcome this decision by the people because it shows how the people hate the Taliban and terrorists," spokesman Sayed Ansari said.
In Helmand's capital, Lashkar Gah, an unknown assailant beheaded the top official dealing with refugee affairs inside his house Sunday, said Daud Ahmadi, a police spokesman.
Abdul Samad Mazari was killed after a few men entered his house pretending to have a meeting with him, Ahmadi said. He blamed the "enemies of Afghanistan" for the murder, government shorthand for Taliban fighters.
Southern Afghanistan is the center of the Taliban-led insurgency. The militants have made a comeback in the last three years after their initial defeat following the U.S. invasion in 2001.