At least three people killed and two other workers trapped after a metro construction site collapsed in Qingdao, east China's Shandong Province, on Monday.

The incident took place at around 5:40 p.m. BJT (0940GMT) at line 4 of Qingdao Metro, which is currently under construction.

An emergency response activated immediately after the incident.

By 1:43 a.m. BJT on Tuesday, rescue team found three bodies.

A rescue operation is underway, and the cause of the collapse is still unclear. 

(Cover: File photo of the construction site of Qingdao Metro.)