Using heavy equipment and even their bare hands, rescuers in Morocco on Sunday stepped up efforts to find survivors of a devastating earthquake that killed more than 2,000 people and flattened villages.

The first foreign rescuers flew in to help after the North African country's strongest-ever quake killed at least 2,012 people and injured more than 2,000, many seriously, according to the official figures.

Friday's 6.8-magnitude quake struck 72 kilometres southwest of the tourist hub of Marrakesh, wiping out entire villages in the hills of the Atlas mountains.

On Sunday an aftershock of magnitude 4.5 rattled already-traumatised residents in the same region.

The mountain village of Tafeghaghte, 60 kilometres from Marrakesh, was almost entirely destroyed, with very few buildings still standing.

Amid the debris, civilian rescuers and members of Morocco's armed forces searched for survivors and the bodies of the dead.

Witnesses saw them recover one body from the ruins of a house. Four others were still buried there, residents said.

"Everyone is gone! My heart is broken. I am inconsolable," cried Zahra Benbrik, 62, who said she had lost 18 relatives, with only the body of her brother still trapped.

"I want them to hurry and get him out so I can mourn in peace," she said.

Many houses in remote mountain villages were built from mud bricks.

In the village of Amizmiz, near Tafeghaghte, a backhoe dragged away the heaviest pieces of rubble before rescuers dug into the dusty debris with their bare hands to remove a body that appeared to be under a quilt.

The two villages lie in Al-Haouz province, site of the quake epicentre, which suffered the most deaths, 1,293, followed by Taroudant province with 452 lives lost, authorities reported.

Citizens on Sunday rushed to hospitals in Marrakesh to donate blood to help the injured.

Spain's defence ministry said an A400 airlifter took off from Zaragoza with 56 rescuers and four search dogs headed for Marrakesh to "help in the search and rescue of survivors."

"We will send whatever is needed because everyone knows that these first hours are key, especially if there are people buried under rubble," Defence Minister Margarita Robles told Spanish public television. (AFP)