A powerful blast targeting an armored NATO convoy in Kabul has killed at least eight people and wounded 28, including three coalition soldiers, officials say.
The Islamic State (IS) extremist group claimed the attack in a statement carried by its Aamaq media arm.
The attack came on May 3 during morning rush hour on a busy road near the U.S. Embassy and NATO headquarters, according to an Afghan Interior Ministry spokesman.
"Unfortunately most of [the victims] are civilians," spokesman Najib Danish said.
NATO said three coalition soldiers had received "non-life-threatening wounds."
"[They] are in stable condition, and are currently being treated at coalition medical facilities," a spokesman for U.S. Forces-Afghanistan said, without confirming their nationalities.
Earlier, a Resolute Support spokesman, U.S. Navy Captain Bill Salvin, said three U.S. service members were wounded in the attack. Resolute Support is a NATO-led train, advise, and assist mission.
The explosion, which NATO said was an improvised explosive device, damaged two of the heavily armored Mine-Resistant Ambush-Protected (MRAP) vehicles carrying the foreign soldiers and left a small crater in the road.
MRAPs, which are designed to withstand large explosions, are routinely used by international forces moving around Kabul.
However, the IS statement said a suicide bomber detonated an explosives-rigged car as the convoy passed an area near the U.S. Embassy.
The local IS affiliate has gathered strength in recent years, and is now at war with both the U.S.-backed government and the much larger Taliban insurgency.
The attack comes just days after a threat by the Taliban to target foreign forces in the spring offensive that it launched last week.
The spring offensive normally marks the start of the "fighting season," though this winter Taliban militants kept battling government forces.
Since the beginning of the year, at least five large attacks have taken place in Afghanistan's capital with hundreds of civilians killed and injured.
U.S. Defense Secretary Jim Mattis, who visited Kabul last month as Washington seeks to craft a new strategy in Afghanistan, warned of "another tough year" in the war-torn country for both foreign troops and local forces.
NATO chief Jens Stoltenberg told a German newspaper on April 20 that the 28-nation alliance was considering boosting its troop strength once more, given the "challenging" security situation.
The United States has around 8,400 troops in the country with about another 5,000 from NATO allies.
Most are taking part in NATO's train, assist, and advise mission, though some are also carrying out counterterrorism missions targeting the Islamic State group and Al-Qaeda.
The Afghan conflict is the longest in U.S. history -- American-led NATO troops have been at war there since 2001, after the ousting of the Taliban regime for refusing to hand over Osama bin Laden following the September 11, 2001, attacks in the United States.