Mohammad Shafi Rahimi, the ministry spokesman, said 26 of the deaths occurred in Jalrez district, 46 km (29 miles) east of Kabul, after the rain washed away hundreds of houses, most of them built of earth.
Four more people died in Kabul, and a total of over 70 were injured in both districts, he said, adding at least 40 other people were missing, according to Reuters.
Afghan Taliban's spokesman Zabihullah Mujahid issued a condolence message, calling on aid groups and the Kabul administration to help the bereaved families.
Last year's monsoon flooding killed dozens of people in Afghanistan, washing away hundreds of houses and livestock.
SKH/PR