Within an hour, Mr. Muhammad’s family knew he had not made it over the pass, and they began calling his cellphone, only to get an out-of-service message.

Mr. Muhammad was alive and conscious in the darkness of his buried Toyota; one of his passengers had been thrown out, and three others were injured. It took him until 3 a.m. Tuesday to find his cellphone, turn it on and call home.

Image A man outside a hospital in Charikar, Afghanistan, grieved for a victim of one of the 17 avalanches. Credit... Altaf Qadri/Associated Press

As he and hundreds of others lay buried, rescuers began arriving by helicopter and on foot.

“We’ve had many avalanches here,” said the Parwan Province police chief, Maulana Sayedkhili. “This is the worst one ever.”

Rescuers from the nearest village found a bus that had been buried, with just the rear bumper sticking out, according to one of the villagers, Azizullah (who, like many Afghans, has only one name). They started digging and found 14 people still alive, those in the back of the bus, closest to the surface. Piled beneath them were 40 dead passengers.

In another car, officials found a dead woman and her seven children, all still alive. At least four other children were reported to have lost their parents in the avalanches. The governor of Parwan Province, Basir Salangi, estimated Wednesday that 50 vehicles remained buried.