Although the earthquakes hit Istanbul on a weekday afternoon, Wednesday is a national holiday here, so schools, universities and public institutions were closed.
This meant that more people than usual were at home when the quake struck.
Worried about aftershocks and whether buildings were safe, hundreds of residents have decided to spend the night outdoors.
In Beşiktaş, one of the city's busiest neighbourhoods, people have gathered in open spaces like the main square.
Selim Ustaoğlu, a university student, was in his dorm room when the tremors began.
"At first I thought I was going to faint," he says. "Then I realized it was an earthquake. I yelled to alert others and ran outside."
He packed a small bag with essentials like a charger, toothbrush and his favourite sweater before heading to the square. "I'm staying here tonight," he says.
"I was in the supermarket with my family when everything started to shake," says Zeynep Akıncıoğlu, another student. "We rushed outside. I don't feel safe going back inside, our building doesn't look strong."The building started to shake violently' - holidaying family
18:11 23 April
published at 18:11 23 April
A woman holidaying in Istanbul with her family tells the BBC that the building she was staying in "started to shake quite violently for what seemed like about five minutes", around Wednesday lunchtime.
Caroline and David Warburton, from Rugby in the UK, are visiting with their two children.
The family - who have been staying on the eighth floor of an apartment block - soon realised it was an earthquake, so gathered their passports and phones and rushed out of the building.
Caroline says children were crying as residents ran down the stairs. They fled to a local park, along with many others, to try and get away from high-rise buildings.
“The children say they could see cracks in the building, and there is a lot of traffic, sirens and fire engines,” Caroline says.
