SHANGHAI (AP) — The first scientist to publish a sequence of the COVID-19 virus in China staged a sit-in protest outside his lab after authorities locked him out of the facility — a sign of the Beijing’s continuing pressure on scientists conducting research on the coronavirus.

Zhang Yongzhen wrote in an online post Monday that he and his team had been suddenly notified they were being evicted from their lab, the latest in a series of setbacks, demotions and ousters since the virologist published the sequence in January 2020 without state approval.

When Zhang tried to go to the lab over the weekend, guards barred him from entering. In protest, he sat outside on flattened cardboard in drizzling rain, pictures from the scene posted online show. News of the protest spread widely on Chinese social media and Zhang told a colleague he slept outside the lab — but it was not clear Tuesday if he remained there.