We’ve now got more images showing what the streets look like after the earthquake hit.

From what we can see, there’s a large crowd on the street. Some people are sitting on the ground, while others are making phone calls.

Burak Abatay
BBC Turkish, reporting from Istanbul

I was in Pendik, one of the large districts on the Asian side of Istanbul, when the earthquake hit.

The 6.2 magnitude quake was the most terrifying experience my father – who has limited mobility – and I have had in a long time.

Everyone in our building rushed outside. While we were still trying to process what had happened, we felt another tremor. People panicked – grabbing their pets, holding their children, helping the elderly.

Istanbul is huge, and people I’ve spoken to say there are too few safe open spaces to shelter in during a disaster.

One person asked: “What will we do if there’s an even bigger earthquake? Where will we go?”

Another, worried about the condition of her very old apartment, said: “I probably shouldn’t go back in tonight. But what am I supposed to do?”

We’re now seeing pictures of a partially collapsed abandoned building in Istanbul’s Fatih district after a series of earthquakes.

It’s not yet known if there are any casualties.

Authorities are urging people not to go near buildings that could be damaged.

Today’s earthquakes struck during a live TV interview on CNN Turk, with presenter Meltem Bozbeyoğlu staying on air as the studio shook.

Visibly anxious and out of breath, Bozbeyoğlu says: “We felt it terribly.”

She then asks someone through her earpiece to call her mother.

“I’m 32 years old and this is the first time I’ve experienced such a big earthquake,” she says.

She leaves her mother a message: “Can you please reach me on WhatsApp.”

“I was frightened, I apologise if I made you panic,” she tells viewers.

You can watch the clip here, external.

Paul Kirby
Europe digital editor

Istanbul sits on the North Anatolian fault line so it is vulnerable to earthquakes. The city has seen deadly tremors before and its residents have long feared an even bigger one.

The Kandilli observatory has put the risk of Istanbul experiencing a 7-magnitude quake by 2030 at 64%.

In 1999, a 7.4-magnitude quake claimed 17,000 lives and last year Turkey’s environment minister warned that Istanbul did not have the capacity to withstand another one.

“One in every five houses in Istanbul, almost 1.5 million, are considered structurally unstable,” said Murat Kurum. The environment minister recently spoke of fighting earthquakes as a matter of national security.

The devastating twin quakes in south-eastern Turkey and Syria in February 2023 were of 7.6 and 7.7 in magnitude and left 55,000 people dead.

Turkish geologist and earthquake expert Naci Görür says today’s earthquakes happened on the Kumburgaz fault.

The Kumburgaz and Adalar faults are the closest to Istanbul, and both are key to the larger earthquake that has long been expected in the city.

Görür says in a post on X that today’s earthquakes are “not the big earthquakes we expect”, which he thinks will be above magnitude seven, but they do add to the stress on the Kumburgaz fault and make it more likely to break.

He calls on the government, Istanbul municipality and the public to work together to prepare the city for earthquakes.

The map below shows the first three earthquakes that struck Istanbul’s Silivri and Buyukcekmece districts earlier today.

They happened in the Sea of Marmara, to the west of the city.

Tom Joyner
Live reporter

Halil Taşkın was working by the water in Istanbul’s Beşiktaş neighbourhood when he felt the quake.

He and his colleague dived under the table and waited for the rumbling to end.

When it was over, Taşkın switched on the TV news and looked out at the crowds gathering in the street below.

“It feels like it was for a long time, but it was only five seconds or 10 seconds,” he tells me. “The news anchor was almost in tears.”

Like many others, he’s terrified of an earthquake in Istanbul, something analysts have warned about for years.

“We are all on tenterhooks,” he says.

Asya Robins
Live reporter

Today’s earthquakes hit the western outskirts of the Istanbul – the Silivri and Buyukcekmece districts.

Although they are quite far out of the city centre, both are prominent suburban areas and tend to receive an influx of residents and visitors in the spring and summer seasons.

Istanbul has also been expanding geographically over the last several years, with many people opting to move to less built up areas, outside the city centre.

Scientists have long said that a big earthquake in Istanbul, which has been expected for years, could hit at any moment.

Having lived there myself for most of my life, and with my family still there, it’s hard not to feel anxious.

Although no casualties have been reported so far, Istanbul residents have long feared this moment, and will be wondering if it’s a sign of a worse earthquake to come.

Paul Kirby
Europe digital editor

The biggest of the tremors to hit Istanbul was felt some 275 miles away (440km) in the capital, Ankara, according to Mayor Mansur Yavas.

It’s a measure of how powerful the 6.2-magnitude quake was.

President Recep Tayyip Erdogan, in his first comments, says he is following events closely.

They are measured on a scale called the Moment Magnitude Scale (Mw). This has replaced the better-known Richter scale, now considered outdated and less accurate.

The number attributed to an earthquake represents a combination of the distance the fault line has moved and the force that moved it.

A tremor of 2.5 or less usually cannot be felt, but can be detected by instruments. Quakes of up to five are felt and cause minor damage.

Anything above a six (which includes the largest quake today measuring at 6.2) is considered strong and can cause severe damage.

Anything above eight causes catastrophic damage and can totally destroy communities at its centre.

Officials from the Istanbul Governorship say they haven’t received any reports of earthquake damage yet.

Authorities are still scanning the city and ask members of the public once again not to approach buildings that might be damaged.

Tom Joyner
Live reporter

Across Istanbul, residents are still reeling from the shock. SelinTüter was at work in an office building on the European side of the city whenthe earthquake hit.

At first she felt the ground give way, sending her off balance. Then she heard a deep rumble, “as if something was punching fromunderneath”.

“When that happened, a lot of people panicked. A lot ofpeople started making a run for it,” she tells me.

She explains that many people in Istanbul are wary of earthquakesfollowing the massive shocks that killed 55,000 people in Turkey and Syria in2023.

Istanbul authorities are warning the public not to enter buildings that might be damaged following the earthquakes.

They advise people to not drive or use their phones unless absolutely necessary.

Interior Minister Ali Yerlikaya says disaster and emergency management teams are starting to assess the impact of the quakes.

We’ve just received the first batch of images from Istanbul, showing people looking worried as they leave buildings to call loved ones:

Turkey’s disaster agency has just recorded another three earthquakes, all in Istanbul’s Buyukcekmece district.

Their website has just crashed – presumably due to high demand – we’ll bring you more details on the specifics as soon as we can.

Paul Kirby
Europe digital editor

Turkey’s disaster agency has recorded a series of tremors in a matter of minutes, all of them along the coast of the Sea of Marmara, and close to Istanbul.

It is the second tremor of 6.2 magnitude that will be most worrying for Istanbul’s 16 million-strong population.

It’s the biggest city in Turkey where a fifth of the country’s population lives.

The interior minister says the quake was felt not just in Istanbul but in surrounding provinces too.

Orla Guerin
Reporting from Istanbul

In my street in Istanbul, neighbours have gathered together, standing away from buildings,some clearly in shock.

There is still no information about any casualties. Ihave felt previous earthquakes in my building, but in my six years living inIstanbul I have never felt one as strong as this.

The building shook. I tookcover for a few seconds inside and then rushed out of the building when theshaking continued. A neighbour says lamps crashed to the floor in herapartment.

Living in Turkey means living with the risk of earthquakes. Buttoday’s quakes have brought fear to many. Memories are fresh here of thedevastating two quakes in southern Turkey in 2023.

We’ve got more now from Turkey’s Disaster and Emergency Management Presidency, which is reporting several earthquakes in Istanbul.

• The first is of 3.9 magnitude and hit the coast of the Silivri district at 12:13 local time (10:13 BST)
• The second is of 6.2 magnitude and hit the same area at 12:49 (10:49 BST)
• The third quake of 4.4 magnitude in Istanbul’s Buyukcekmece district hit at 12:51 local time (10:51 BST)

Orla Guerin
Reporting from Istanbul

No word yet of any casualties.