The new jolt was registered 24 kilometres (15 miles) north of the port city of Durres and 42 kilometres northwest of the capital, Tirana. There were no immediate reports of casualties or damage.
The aftershock comes a day after the strongest earthquake to hit the small Balkan nation in decades killed at least 32 people and injured hundreds.
The 6.4-magnitude quake struck as people were still sleeping in their homes on Tuesday morning, tearing down several buildings. Rescuers are combing through debris in search of survivors.
Albanian Prime Minister Edi Rama declared Thursday a national day of mourning. Seismologists in nearby Serbia said that aftershocks could be felt across the Balkans for over a month.