KABUL, AFGHANISTAN — Shattering a nearly three-month hiatus on attacks in the Afghan capital, a suicide bomber driving a minivan packed with explosives struck a Western convoy on a busy road Tuesday. The powerful blast killed at least 18 people, including five American service members.
A sixth foreign soldier, whose nationality was not immediately disclosed, also was among the dead.
The explosion occurred at 8 a.m., when many people were on their way to work. A crowded passenger bus was caught up in the carnage, with many aboard killed or injured.
The thunderous echo reverberated across much of the city. The massive blast carved a deep crater in the road in the shadow of a ruined imperial palace on Kabul's western edge, overturning cars and scattering shrapnel and body parts over a wide area; police said all that was left of the attacker's vehicle was the engine block.
"Pieces of people covered the road -- heads and hands and limbs," said a 73-year-old guard named Osain, who worked at nearby Kabul University.
The convoy consisted of unmarked armored SUVs, often used to transport military officers and diplomats around the city. One was flipped end over end by the force of the explosion, and the one behind it was reduced to a scorched hulk. Five military vehicles in all were damaged, along with more than a dozen civilian ones.
The North Atlantic Treaty Organization, the U.S. Embassy and the European Union condemned the attack, in which -- as in many bombings targeting convoys or military installations -- noncombatants took the brunt.
Afghanistan's Interior Ministry described 12 of the dead as "innocent civilians" and said nearly 50 other people, mainly passersby, were hurt.
The Taliban claimed responsibility for the bombing, the first major attack in the capital since February, when assailants killed 16 people in a strike on two small guesthouses.
Security has been tightened since that assault, but bombers routinely penetrate even the most heavily guarded precincts of the capital.
An attack like Tuesday's would have been difficult to plan; Afghan and U.S. officials said the bomber probably cruised the area, aided by "spotters," before stumbling upon a prime target.
The bombing left many residents feeling rattled and insecure. Afghans complain that the government seems incapable of preventing insurgent strikes in the heart of Kabul, although police often tout the breaking up of suicide cells and the capture of other would-be attackers.
"Such things are inhuman," said 27-year-old university student Fazel Ahmad. "Attacks like this are such an affliction that people aren't safe in Kabul. We can't walk free."