CASABLANCA, Morocco - A strong 6.8-magnitude earthquake rattled Morocco late Friday, according to the US Geological Survey, causing people to flee their homes in a panic.

The quake hit 44 miles (71 kilometres) southwest of Marrakesh at a depth of 18.5 kilometers at 11:11 pm (2211 GMT).

It sent debris flying into narrow alleyways and items tumbling off shelves, according to video posted on social media.

The earthquake was also felt in the coastal cities of Rabat, Casablanca and Essaouira.

"There's not too much damage, more panic. We heard screams at the time of the tremor," a resident of Essaouira, 200 km west of Marrakech, told AFP by telephone.

"People are in the squares, in the cafes, preferring to sleep outside. Pieces of facades have fallen".

USGS's PAGER system, which provides preliminary assessments on the impact of earthquakes, issued an orange alert for economic losses, estimating significant damage is likely, and a yellow alert for shaking-related fatalities, indicating some casualties are possible.

USGS said that "the population in this region lives in structures that are highly vulnerable to earthquake shaking."

There were no immediate reports of casualties.

Internet connectivity was disrupted in Marrakesh due to power cuts in the region, according to global internet monitor NetBlocks.

Morocco experiences frequent earthquakes in its northern region due to its position between the African and Eurasian plates.

In 2004, at least 628 people were killed and 926 injured when a quake hit Al Hoceima in northeastern Morocco.

The 1980, the 7.3-magnitude El Asnam earthquake in neighbouring Algeria was one of the largest and most destructive earthquakes in recent history. It killed 2,500 people and left at least 300,000 homeless.