This is the heart-stopping moment kids were seen playing on a balcony without railings.

The two toddlers were seen standing dangerously close to the edge of the third-floor balcony outside a market in Samut Prakan province, Thailand on March 22.

In the video, onlooker Sitti Kawicha shouted at the young boys, aged two and three, and told them to climb back into the room, but the kids continued to frolic in the unfenced area.

The four-storey commercial building where the children live has its ground floor opened as a tuck shop, while the rest of the floors above are open for rent.

A neighbor said: 'The kids’ parents work in the market. We often have to warn the children to stay away from the balcony, but they always return to the same spot in the following days.’

The kids' father Sukri Samaul, 33, said: ‘My wife and I work at the wet market and their grandmother watches over them. I never knew they often played on the balcony.

‘I believe my mother-in-law must have been busy doing chores when this happened. I would like to apologise to the public. I will take better care of my children and block the window for their safety.’