A powerful earthquake measuring 6.0 magnitude struck off Ecuador's disaster-stricken coast on Thursday, April 21 as survivors of an earlier deadly quake that killed 587 people clamored for food, water and medicine in parts of the disaster zone, Reuters reports.

The latest quake hit about 100 km (62 miles) north-northwest of Portoviejo and at a depth of 10 km (six miles), said the U.S. Geological Survey. There were no immediate reports of damage and there was no tsunami warning.

President Rafael Correa said on Twitter that three aftershocks were registered on Thursday night, adding "have strength!".

Saturday's deadly quake was a massive 7.8 magnitude.

"We're trying to survive. We need food," said Galo Garcia, a 65-year-old lawyer as he waited in line for water from a truck in beachside village of San Jacinto. "There's nothing in the shops. We're eating the vegetables we grow."

A crowd nearby chanted, "We want food."

Correa's socialist government, facing a mammoth rebuilding task at a time of greatly reduced oil revenues in the OPEC nation, said there was no lack of supplies, just problems with distribution that should be quickly resolved.

The government quickly moved supplies to the main towns and set up shelters for more than 25,000 people in soccer stadiums and airports, but shattered roads have impeded the operation.

On streets near Pedernales, one of the worst-hit towns, children from rural areas held signs begging for food. Many people left villages to seek help, and those who stayed behind felt the pinch.

"All of us here have been marginalized. The others are receiving things, but we're not," said Darwin Gachila, 33, as he cradled his baby daughter, flanked by his wife and two other children in the small village of Cojimies.

A government official at a food storage point outside the town of Pedernales asked a supplicant, Jose Gregorio Basulor, 55, to stay calm. "I can be patient but not the children!" he shouted back. "They are crying."