A blast near the U.S. Embassy in Kabul has killed at least eight people and wounded 28, in an attack on a convoy of foreign forces, Afghan officials say.
Interior Ministry spokesman Najib Danish confirmed the toll from the attack, which came during the busy morning rush hour, saying, "Unfortunately most of [the victims] are civilians."
The attack hit a group of armored personnel carriers used by the NATO-led Resolute Support mission.
One security source told the media the blast came when a white Toyota Corolla exploded as the convoy drove by. It was not immediately clear if it was a car bomb or a suicide attack.
A Resolute Support spokesman, U.S. Navy Captain Bill Salvin, said three U.S. service members were wounded in the attack.
The heavily armored Mine-Resistant Ambush-Protected (MRAP) vehicles that coalition forces use to travel in Kabul appeared to suffer only relatively minor external damage, and were able to return to a coalition base under their own power, he said.
But the blast also destroyed or badly damaged a number of civilian vehicles nearby.
Witnesses said blood and clothing could be seen on the ground at the explosion site.
"We are checking the details," Danish said. A Health Ministry spokesman confirmed the toll, but could not say whether the victims were foreign soldiers or civilians.
There was no immediate claim of responsibility for the attack, which 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.
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.
The United States has around 8,400 troops in the country with about another 5,000 from NATO allies.
With reporting by dpa, AFP, Reuters, and AP