TikTok user @lil_vb_ was filming at Manly Beach, Sydney, as lifeguards instructed swimmers to exit the sea as a swarm of blue bottle jellyfish (AKA the Portuguese man o' war) washed up on the shore.

The filmer told Newsflare: "I was laying on the sand on Manly beach in Sydney, when over the loud speaker, a lifeguard warned people to get out of the water as a huge amount of blue bottle jellyfish had just washed up onshore.

"I went to see for myself and I was met with the most amount of blue bottle jellyfish I had ever seen. Walking up the shore, I noticed many people getting stung. So I decided to make a video, noting how there were many people at the beach on a beautiful Summers day, yet not many people were in the water.

"Shortly after I recorded the video, because the water was so warm, I decided to go in anyways, and I got stung."

I was laying on the sand of Manly beach in Sydney, when over the loud speaker, a lifeguard warned people to get out of the water as a huge amount of blue bottle jellyfish had just washed up onshore. I went to see for myself and I was met with the most amount of blue bottle jellyfish I had ever seen. Walking up the shore, I noticed many people getting stung. So I decided to make a video, noting how there were many people at the beach on a beautiful Summers day, yet not many people were in the water. Shortly after I recorded the video, because the water was so warm, I decided to go in anyways, and I got stung.