The drones that slammed into buildings and hit other locations in Moscow this week were the second batch to rattle the Russian capital in a month. It's still not clear who's behind them, and what the goal is. Here's what we know.
People in Russia's Belgorod border region have been at the forefront of Moscow’s invasion of Ukraine since the very beginning. Nerves were already fraying even before last week's cross-border raid by militants aligned with Ukraine’s government.