Four people working on the 487MW Sopladora hydroelectric project in Ecuador have been killed in an explosion.

Newswires have reported that the victims were explosives experts from China and were working in a tunnel at the time of the blast. The cause of the explosion is under investigation.

The Sopladora project is being part financed by China and is expected to be complete in 2015. The project is is the third of four hydropower station projects being developed on the Paute River in the Azuay region.