At least 632 people have been killed and hundreds injured following a 6.8 magnitude earthquake in Morocco, state TV says.
Many of the fatalities are said to be in hard-to-reach areas south of Marrakech.
The epicentre was high in the Atlas Mountains – about 43 miles (70km) away from Marrakech, a popular tourist destination.
Reaching people in remote villages, where old, traditional buildings may be more likely to collapse, will be a key focus of the rescue effort on Saturday.
Powerful earthquake kills at least 632 people – follow latest
The earthquake struck late on Friday – damaging buildings in major cities and sending panicked people pouring into the streets.
At least 329 people were injured and are being treated in hospital.
Witnesses in Marrakech, which is a UNESCO World Heritage Site, told the Reuters news agency that some buildings have collapsed. Big cracks were seen in a section of the medieval city’s walls.
Local television stations broadcast pictures of a fallen mosque minaret, with rubble lying on smashed cars. Others were seen screaming as they ran out of shopping centres and restaurants.
Officials are working to clear roads so ambulances and aid can reach those affected – but large distances between mountain villages mean it will take time to learn the full extent of the damage.
Local media reported that roads leading to the mountain region were jammed with vehicles and blocked with collapsed rocks, slowing rescue efforts.
Montasir Itri, a resident in the mountain village of Asni not far from the epicentre, said most houses were damaged – adding: “Our neighbours are under the rubble and people are working hard to rescue them using available means in the village.”
Local journalist Rida Fakhar was in Marrakech when the earthquake struck and told Sky News it was much more powerful than other tremors he has felt.
“It was very strong, I’ve never seen something like it,” he said.
Aftershocks have been reported – with men, women and children staying out in the streets, frightened of further quakes.
According to the US Geological Survey (USGS), the earthquake was at a relatively shallow depth of 11.5 miles (18km).
This is one of Morocco’s strongest earthquakes in years – and although they are relatively rare, a 5.8 magnitude tremor in 1960 caused thousands of deaths.
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Building laws were changed after that earthquake, Sky News’ Africa correspondent Yousra Elbagir said, speaking from Johannesburg.
“But Marrakech is a historic area and the earthquake is just south of the city, so a lot of old buildings have collapsed.
“There are buildings that are centuries old, it’s a very historic place.”
Marrakech has been an area of pilgrimage and migration for centuries, she said, with many people travelling there to visit old Sufi sites.
“At the moment on the ground, the police, the army, the firefighters, they’re all deployed trying to work as quickly and as effectively as quickly as possible.”
This is the most deadly earthquake to hit the country since 2004 – but that was “nowhere near as strong as this 6.8 magnitude earthquake”, she said.
The number of dead is expected to rise through the day as more people are uncovered from the rubble.
The earthquake was felt as far away as Portugal and Algeria.
Morocco has not yet asked for help from other countries, but the United Nations has said it is ready to assist if needed.