REUTERS, Caracas

Rescue teams raced on Sunday to find more survivors of the two powerful earthquakes that struck Venezuela this week, with signs of life bringing occasional relief to a grim quest to whittle down a list of tens of thousands missing.

The death toll from Wednesday’s twin earthquakes neared 1,500 people as foreign rescue teams poured into La Guaira, the hardest-hit state of a country long mired in a deep political and economic crisis. A strong aftershock of 4.6-magnitude struck north of Caracas yesterday.

A father and his son were pulled out alive from the rubble of a collapsed building on Sunday. “There exists a window of roughly three days, 72 hours, where the probability afterwards decreases that you can save people alive,” said Sebastian Eugster, the leader of the Swiss rescue team.

The 80-strong team had found multiple people alive in the rubble thanks to alerts from their eight search dogs, but had not been able to pull them out in time to save them, he added. Saturday evening marked 72 hours since the quakes.

Dozens of buildings collapsed into piles of sand and rubble in the coastal state, about 40 km (25 miles) north of Caracas.