The death toll now stands at 150, the official Moroccan news agency MAP reported on Tuesday.
The previous toll from MAP had been 82 dead.
The quake early this morning has destroyed five adjacent villages, particularly Ayt Qamra village, which was completely leveled down, Aljazeera correspondent in Morocco said.
"Moroccan authorities have launched an air bridge between Rabat and al-Hasima to transfer medical aids and save the injured," added the correspondent.
The US Geological Survey said the earthquake measured 6.5 on the Richter scale.
The quake struck at around 2:30am (02:30 GMT) and was felt in the areas of al-Hasima, the tourist city of Fez in the interior and Taza.
The US Geological Survey (USGS) said there had been hundreds of small quakes in the North African region since 1990, but this was the biggest since one of 6.0 struck in 1994.
Strait of Gibraltar
USGS spokesman Butch Kinerney said the earthquake's epicentre was in the Strait of Gibraltar separating Morocco and Spain, and about 300km northeast of the Moroccan capital Rabat.
"We could definitely see the potential for some fairly significant damage from this earthquake," he said.
The National Geographical Institute in nearby Spain said the quake was centred 15km southeast of the port of al-Hasima, 50km west of the Spanish-ruled north African enclave of Melilla.
The Spanish report estimated the earthquake's intensity at 6.1 points on the Richter scale.
"We could definitely see the potential for some fairly significant damage from this earthquake"
It said the event was felt in both Melilla and the southern Spanish regions of Andalusia and Murcia, although no damage was reported from any of those regions.
The Europa press agency said the situation appeared to be normal in Melilla.
Morocco's worst recorded earthquake was in 1960. It destroyed the southern Atlantic city of Agadir, killing 12,000 people.