Over 770 people have been killed, and 4,700 people injured after the capital Algiers and towns to the east were affected on Wednesday evening.
The centre of the quake was the town of Thenia, about 60 kilometres (40 miles) east of the capital.
Tremors, or smaller earthquakes, continued for two hours after the first one hit.
This meant that people in the area were afraid to return to their houses for a long time.
There is no electricity in much of the area affected by the disaster, and phone lines are overloaded with people trying to get through to friends and family.
Rescue workers are trying to save many people trapped in the rubble of ruined buildings.
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