NEW DELHI, May 20 (Xinhua) -- At least five people were killed and two others critically injured Tuesday after rocks caved in inside a stone quarry in the southern Indian state of Tamil Nadu, police said. 

The stone quarry collapsed in Singampunari of Sivagangai district, about 418 km southwest of Chennai, the capital city of Tamil Nadu. 

Following the collapse, a police team and rescuers from the fire and emergency department rushed to the site to carry out rescue efforts and pull the workers trapped under the debris. 

"Three bodies were first extricated from the debris, and later on, four others were pulled out in an injured condition," a police official said. "Of the injured, two succumbed on the way to the health facility and two others were admitted to the hospital in critical condition." 

Police have registered a case and ordered an investigation into the incident. 

The victims were identified as workers at the stone quarry. Reports said the workers were 30 feet deep in the quarry when the rocks fell upon them.