Photos circulating on Twitter Thursday afternoon show two banners hung on an overpass of a major thoroughfare in the northwest of the Chinese capital, protesting against Xi's unrelenting zero-Covid policy and authoritarian rule.

"Say no to Covid test, yes to food. No to lockdown, yes to freedom. No to lies, yes to dignity. No to cultural revolution, yes to reform. No to great leader, yes to vote. Don't be a slave, be a citizen," reads one banner.

"Go on strike, remove dictator and national traitor Xi Jinping," reads the other.

The photos and videos also show plumes of smoke billowing from the bridge, and a voice recording of the protest slogans played on loudspeaker.

CNN cannot independently verify the images and footage, but has geolocated them to Sitong Bridge, an overpass on Beijing's Third Ring Road in Haidian district.

When CNN arrived at Sitong Bridge around 3.30 p.m. Thursday, no protesters or banners could be seen. However, a large number of security personnel were on the overpass and in the vicinity. Security personnel were also spotted patrolling every overpass CNN drove by on the Third Ring Road.

Chinese authorities have yet to comment on the incident. CNN has reached out to Beijing police for comment.

The protest sent China's stringent online censorship into overdrive.