KABUL, Afghanistan — A Taliban suicide bomber rammed a vehicle loaded with explosives into an armored NATO bus Saturday on a busy thoroughfare in Kabul, killing 17 people, including a dozen Americans, in the deadliest strike against the U.S.-led coalition in the Afghan capital since the war began.
The blast occurred on the same day that a man wearing an Afghan army uniform killed three Australian soldiers and an Afghan interpreter in the south — attacks that show the resiliency of the Taliban insurgency and are likely to raise new doubts about the unpopular 10-year-old war.
A spokesman for the fundamentalist Islamic movement, which was ousted in the 2001 invasion for its affiliation with al-Qaida, claimed responsibility for the Kabul attack, saying the bomber had used 1,540 pounds of explosives.
The Taliban and related groups have staged more than a dozen major attacks in Kabul this year, including seven since June, in an apparent campaign to weaken confidence in the Afghan government as it prepares to take over its own security ahead of a 2014 deadline for the United States and other NATO countries to withdraw their troops or move them into support roles.
After the bomber struck in Kabul, heavy black smoke poured from the burning wreckage of an armored personnel carrier, known as a Rhino. The bus had been sandwiched in the middle of a convoy of mine-resistant military vehicles when it was hit along a four-lane highway often used by foreign military trainers in the southwestern part of Kabul.
The landmark Darulaman Palace, the bombed-out seat of former Afghan kings, was the backdrop to the chaotic scene: Shrapnel, twisted pieces of metal and charred human remains littered the street.
U.S. soldiers wept as they pulled bodies from the debris, said Noor Ahmad, a witness at the scene. One coalition soldier was choking inside the burned bus, he said.
"The bottom half of his body was burned," Ahmad said.
NATO said five of its service members and eight civilian contractors working for the coalition died in the attack.
All 13 were Americans, the Associated Press reported, citing an unnamed U.S. defense official who spoke on condition of anonymity to release the information before a formal announcement. However, Lt. Col. Christian Lemay, a Canadian defense spokesman, told the AP that one Canadian soldier was among the troops killed. The discrepancy could not immediately be reconciled.
It was the deadliest single attack against the U.S.-led coalition across the country since the Taliban shot down a NATO helicopter on Aug. 6 in an eastern Afghan province, killing 30 U.S. troops, most elite Navy SEALs, and eight Afghans.
The Afghan Ministry of Interior said four Afghans, including two children, also died in Saturday's attack. Eight other Afghans, including two children, were wounded, said Kabir Amiri, head of Kabul hospitals.
The Taliban identified the bomber as Abdul Rahman and said he was driving a Toyota Land Cruiser SUV containing 1,540 pounds of explosives.
In all, there were three attacks Saturday against NATO and Afghan forces across the country.
A teenage girl also blew herself up as she tried to attack an Afghan intelligence office in the capital of Kunar province, a hotbed of militancy in northeast Afghanistan along the Pakistan border, the coalition said. In the third attack, Afghan Defense Ministry spokesman Mohammad Zahir Azimi said officials were investigating whether the man who opened fire on a joint NATO-Afghan base in the restive southern Uruzgan province was an actual soldier or a militant in disguise.
The Australian Broadcasting Corp. said the attack occurred during a morning parade at a forward patrol base in southern Kandahar province, and the gunman wearing an Afghan army uniform was later killed. The discrepancy in the location of the attack could not immediately be clarified.
In Canberra, the Defense Department said three Australian soldiers and their Afghan interpreter were killed in the attack, and seven Australian soldiers were wounded.
"It's a huge loss," said U.S. Ambassador Ryan Crocker. "Our deepest sympathies go out to their comrades and families, but it will not deter us from our mission. It's a shock, but we will not let these guys win."
Just a day earlier, the Pentagon issued a progress report saying that the number of enemy-initiated attacks in Afghanistan was trending downward. Since May of this year, the monthly number of these attacks has been lower than the same month in 2010, something not seen since 2007, it said.
However, the Pentagon also noted that the insurgency's havens in Pakistan and the limited capacity of the Afghan government could jeopardize the gains.