As Venezuela begins counting the cost of its deadliest quake disaster in over a century, a shattered economy and struggling health system threaten to slow recovery efforts.

A 7.2-magnitude earthquake and a 7.5-magnitude were less than a minute apart, said the U.S. Geological Survey. The second earthquake was the largest to hit the country since 1900.

Several earthquakes shook Venezuela's capital of Caracas on Wednesday afternoon,witnesses reported.

US Geological Survey estimates 44 per cent chance fatalities could exceed 10,000