EFEManabi, Ecuador

Four days after a magnitude-7.8 earthquake devastated Ecuador's northern coast, rescue workers remain hopeful of finding survivors amid the twisted metal and rubble of fallen homes and buildings.

Christian Rivera, director of Quito's Special Operations Center, said that hope stems from the discovery by the capital city's firefighters and Metropolitan Police force of 12 survivors among 98 bodies they recovered in the coastal towns of Tarqui, Canoa, Jama, El Matal, Flavio Alfaro, Estero Seco and Pedernales.

"We remain hopeful there are people still alive," Rivera told EFE on Wednesday, saying the focus of rescue efforts was on the hotel zones.

"Devastation. Everything is on the ground, cars destroyed, people receiving humanitarian aid, lots of cars of rescue teams coordinating actions, heavy machinery clearing rubble," Rivera said from the pier in Pedernales, a tourist town in Manabi province.

Pedernales was one of the areas hardest hit by Saturday evening's earthquake, which has been followed by a total of 541 reported aftershocks, including two Wednesday morning that measured magnitude-6.1 and magnitude-6.3 and caused more houses to crumble.

Rivera repeatedly described the situation as difficult, but he expressed gratitude to local residents who have offered rescue workers shelter at schools and churches, as well as to business owners who have allowed the use of their warehouses.

The earthquake, one of the most powerful in the history of the Andean nation, has left around 500 dead, more than 4,000 injured and dozens missing.

But the tragedy has also revealed the generosity of ordinary Ecuadorians, who have collected food and other supplies and written messages of encouragement on canned goods donated to earthquake victims.