HERAT, Afghanistan — One friend was known for his guitar skills, strumming his instrument during late nights of student life. A second worked for a local television station part time. A third had left the university and his friends for a semester, trying to escape the war through the migrant route to Europe — only to be deported halfway, returned to his studies in an Afghanistan in flames.

Reunited, the friends sat in the middle section of a packed bus early Wednesday morning, occupying seats 25 to 28. The coach made its way from the western city of Herat to Kandahar in the south. They were taking advantage of a brief summer break to attend an engagement ceremony of a fourth friend, also traveling with them.

But for civilians caught in Afghanistan’s spiraling conflict, the road between life and death is narrow — and often mined. When the bus arrived in a desert in restive Farah province, barren and quiet in the dawn light, it struck a roadside bomb.

In an inferno of fire and blood, 35 passengers were killed and most of the 27 remaining were badly broken and bloodied. There are no shops, homes or even trees for miles. When the first witnesses arrived, some of the wounded were wailing and others were trying to escape through the broken windows of the bus. Soon, the asphalt was strewn with bodies — young and old, in jeans and burqas, all in blood.