Russian police arrested prominent opposition leader Alexei Navalny at the Moscow airport as he arrived back in Russia Sunday. Navalny, a vocal critic of Russian President Vladimir Putin, was poisoned last August with Novichok, a banned military-grade nerve agent. He’d been staying in Germany after nearly dying. A judge on Monday ordered he be put in pretrial detention for a month. In response, Navalny released a video clip urging supporters to protest.

Alexei Navalny: “So I’m calling upon you. Don’t be silent. Resist. Take to the streets. Nobody would protect us but ourselves. But we are so many that if we want to achieve something, we will achieve it.”