Singapore's underground oil store

One hundred and thirty metres below the sea bed of Singapore lies a most unusual construction site.

The project, dubbed the Jurong Rock Caverns, is costing about $740m (£450m).

It is currently in its first phase of construction and is due for completion in 2014.

Five oil storage caverns are being dug out under the seabed of Banyan Basin, off Jurong island, a series of mostly-reclaimed islands that house most of Singapore's petrochemical industry.

The BBC's Sharanjit Leyl reports.