Patients wait outside a clinic that was evacuated after tremors were felt resulting from an earthquake in Ecuador, in Cali, Colombia, April 16, 2016.[Photo/Agencies]

The areas worst affected include Pedernales, which draws tourists with beaches lined with palm-trees and tropical thatch-hut restaurants, as well as nearby Cojimies.

"There are villages that are totally devastated," Pedernales' mayor, Gabriel Alcivar, said in a radio interview. "What happened here in Pedernales is catastrophic."

Ramon Solorzano, 46, a car parts merchant in the city of Manta, said he was getting ready to leave the city with his family.

"Most people are out in the streets with backpacks on, heading for higher ground," he said, speaking in a trembling voice via a WhatsApp phone call. "The streets are cracked. The power is out and phones are down."

The quake struck at a depth of 20 km (12.4 miles), and was followed by 55 aftershocks.