Residents were left in shock as they spotted an unidentified reddish-brown substance gushing out from the ground in eastern China.

The video was filmed in the city of Nanjing in Jiangsu Province on October 28.

The mysterious liquid bubbled up, rapidly covering a significant portion of the road, and forcing vehicles and pedestrians to reroute.

The filmer was heard saying: " What is this? Anyone knows?"

An official stated that upon receiving reports from the public, they dispatched community workers to investigate the scene and set up barricades. The exact cause was still under investigation at the time.

However, local traffic police later clarified that the sudden eruption was due to foam from underground construction work, not mud as initially thought, and assured the public it had been cleared up.

Following this, the Daguang Road Street Office further confirmed that the incident was caused by grouting for subway shield construction.

They explained, "The construction created a hole on the surface, which has been repaired overnight. The barriers were removed this morning, and traffic has returned to normal."

The video was provided by local media with permission.

10月28日，江苏南京，秦淮区大光路一路段，地下持续有不明物质喷涌而出。
目击市民拍摄的现场视频显示，公路中间，持续有红褐色物质从地下冒出来，涌上地面，占据了大面积道路，车辆、行人不得不改道。“不知道怎么回事，也不知道是什么东西。”拍摄者疑惑道，并称喷涌的物质看起来有些像泥浆。
29日，大光路街道办一名工作人员表示，接到群众相关反映后，他们已联系社区工作人员前往现场进行查看，也设置了围挡，具体原因，还待进一步了解。
当地交警部门回复称，经现场查看，喷出的物质为施工方作业造成的泡沫，“地下施工作业，往外冒出泡沫，不是泥浆，已经清理过了。”
随后，大光路街道办工作人员也回复称，经过现场查看了解，为地铁盾构注浆造成，“施工给地面形成一个孔，已经连夜修复，今早围挡已经拆除，恢复了正常通行。”