1.   He said the drainage tunnel was drilled through rock under a mountain without any concrete reinforcement.

2.   It said waste was discharging through a drainage tunnel beneath the pit, which was previously plugged and sealed but gave way under stress.

3.   Officials shut the mine in April after a drainage tunnel in its containment pond collapsed, discharging millions of tons of liquefied waste into two rivers.

4.   Officials shut down the mine in April after a drainage tunnel in its containment pond collapsed, discharging millions of tons of liquefied waste into two rivers.

5.   The investment projects include construction of a railroad bridge across the Amu Darya River and a drainage tunnel under the capital Ashgabat.