KYIV, Ukraine (AP) — The Russian military's top brass came under increasing scrutiny Wednesday as more details emerged of how at least 89 Russian soldiers, and possibly many more, were killed in a Ukrainian artillery attack on a single building.

The scene last weekend in the Russian-held eastern Ukrainian town of Makiivka, where the soldiers were temporarily stationed, appears to have been a recipe for disaster. Hundreds of Russian troops were reportedly clustered in a building close to the front line, well within range of Ukraine's Western-supplied precision artillery, possibly sitting close...