The U.S. city of New Orleans is in a state of heightened alert as hurricane Isaac pounds the region with strong winds and torrential rains.

The key port city in Louisiana saw nearly 500 millimeters of rain on Wednesday. More than 60 percent of households in the city lost power and as a result, a dawn-to-dusk curfew was proclaimed by the city's mayor. People residing in low-lying areas were also ordered to evacuate.

No casualties have been reported, but financial losses from the storm are expected to surge rapidly.

Insurance industries estimated that losses due to suspension in oil production and industrial activities in the southern port city will stand at around two-and-a-half billion dollars.