Never before seen footage shows the shocking moment an explosion rocked the port of Lebanon's capital city, Beirut, on Tuesday (August 4), at approximately 6 pm local time.

The HD 4k video, recorded on a tripod by Agoston Nemeth, a 42-year-old therapist from Budapest, Hungary, shows loud rumbling, as black smoke engulfs the sky, before a huge mushroom cloud and visible blast wave blows out the windows, rushing towards the camera and knocking it over.

Nemeth's shocking footage was captured on the terrace of his home, on the 13th floor of building next to St George Hospital, only 850 meters from the explosion.

He told Newsflare: "That evening, I heard some firework type of noise. It's not unusual here in Lebanon but it was so intense, so loud that I went out to the terrace. I noticed flames and in a warehouse in the port. I heard them first, like the sound of small fireworks. It was about 5.40 pm and I went out and took some pictures from the terrace. I thought the firefighters would arrive soon and I wanted to record them coming and put out the fire. I left my iPhone outside on the terrace, propped up on a handrail, and left it recording, at around 5.50 pm.

"At 6 pm I had my therapy session with a client. Five minutes after I started the session, I heard a bigger explosion. I noticed it had escalated, so I told my client to stay there and I checked the explosion. I was getting nervous. I went out with my camera and I noticed it was getting bigger and bigger, some huge flames came out and suddenly there was this, 'boom.'

"It was something I could not get away from. I experienced this white-hot glass exploding. I don't know if I jumped or the shock waves pushed me and I found myself on the floor. I don't know how much time passed. I noticed shattering glass and people screaming. I looked around and saw this huge orange cloud above me.

"Then I stood up and took some pictures and video. I didn't know if the building would collapse. Shortly after my fiancé called me, she was four or five kilometers away but also felt the blast around her."

Nemeth also told Newsflare about his now damaged apartment, that he has lived in since January 1, 2019, with his Hungarian fiancé, who works for an international organisation.

"After the blast, I saw our apartment completely demolished, completely destroyed. Clothes, books, the bed, furniture - everything mixed with glass," he said.

"Yesterday (August 6) we went back to the apartment to rescue some stuff. I saw the table on the terrace - there was one piece of glass inside the tabletop that was one centimetre deep. When my fiancee arrived she could see the metal elevator door was displaced. And I saw the walls and stairs had blood, handmarks with blood, people were all over the place injured. I could smell blood. My apartment is still in pieces now, three days on."

Nemeth continued: "Once you visit Lebanon, you fall in love with it. I cannot pinpoint one thing, it's the whole thing. It's terrible. I'm in shock, the first day I was in 'doing' mode, I was so active I couldn't even sleep, maybe two hours. The next day I was very active but I was completely numb. I had to check my whole body to see if it hurt. I started to realise how lucky I was when I saw the glass stuck in the table. And now I feel guilty. Not everybody was that lucky. I was extremely lucky to be this close but didn't get hurt at all. I have some bruises in my shoulder but that's all, most likely from when the blast waves pushed me to the ground."

On Friday (August 7) Lebanese Health Minister Hamad Hassan confirmed that 154 people were killed in the explosion and more than 5,000 residents were injured.

Beirut explosion HD 4k slow motion frame by frame tripod stable, filmed on a mobile phone, iPhone SE

I am Agoston Nemeth, from Budapest, Hungary, aged 42. I am a therapist. My fiancee, also from Hungary. I live in a building next to St George Hospital. It's 850m in a straight line from the explosion. We've been living in Beirut since Jan 1, 2019.

That evening, I noticed flames in the warehouse in the port - I saw them, the flames and smoke. I heard them first, like a sound of small fireworks. It was about 5.45pm. And I thought the firefighters would arrive soon and I wanted to record them coming and put out the fire. I started filming and left my iPhone outside on the terrace, propped up on a handrail, and left it recording, at around 5.50pm local time.

At 6pm I had my therapy session with a client.

I was inside the apartment, we were living in a 13th storey building on the top floor. We have a terrace. I heard some fireworks type of noise. It's not unusual here in Lebanon. It was so intense, so loud that I went out to the terrace and saw the smoke coming up.

I thought the firefighters would come and put out the fire and I wanted to witness that. So I put my camera there and talked to my clients.

Five minutes after I started the session, I heard a bigger explosion. I noticed it had escalated, so I told my client to stay there and I checked the explosion, I was getting nervous. I went out with my camera. And I noticed it was getting bigger and bigger, some huge flames came out and suddenly there was this, "Boom."

It was something I could not get away from. I experienced this white sphere expanding and rapidly approaching to me. I saw in a slow motion all the glass exploding and roof tiles flying. I don't know if I jumped or the shock waves pushed me and I found myself on the floor. I don't know how much time had passed

I noticed shattering glass and people screaming. I looked up and saw our apartment completely demolished, completely destroyed. Clothes, books, the bed, furniture - everything mixed with glass.

I looked around and saw this huge orange cloud above me.

Yesterday we went back to the apartment to rescue some stuff. I saw the table near me in the terrace - there was one piece of glass inside the table top, one centimetre deep.

I was lying on the terrace.

Once you visit Lebanon, you fall in love with it. I cannot pinpoint one thing, it's the whole thing. It's terrible. I'm in shock, the first day I was in "doing" mode, I was so active I couldn't even sleep, maybe two hours. The next day I was very active but I was completely numb. I had to check my whole body to see if it hurt. I started to realise how luck I was when I saw the glass in the table. And now I feel guilt. Not everybody was that lucky. I was extremely to be this close but didn't get hurt at all. I have some bruises in my shoulder but that's all, most likely from when the blast waves pushed me to the ground. I was beside the table. Then I stood up and took some pictures and video. I didn't know if the building would collapse. Shortly after my fiancee called me, she was four or five km away but also felt the blast and the push around her. And glass where she was broke.

My apartment is still in pieces now, three days on.

When my fiancee arrived she could see the metal elevator door was displaced. And I saw the walls and stairs had blood, handmarks with blood, people were all over the place injured. I could smell the blood while going down and meet my fiance.