Shoppers were terrified when a huge wall of arcus clouds towered over a market in southern Thailand.

Student Sisira Nunklam was with her family buying food when the sky darkened in her hometown in Nakhon Si Thammarat province on May 2.

Footage shows the imposing grey mass floating in the air for several minutes before it finally dissipated.

Sisira said: ''The sky always becomes gloomy before a thunderstorm but this was not like anything I'd seen before. It was scary.''

Market stall traders packed away their goods to prepare for heavy rain which appeared shortly after the imposing cloud.

An Arcus cloud is a low, horizontal cloud formation which is most frequently formed along the edge or "gust fronts" of thunderstorm outflow.

This cloud formation is also known as wall clouds, funnel clouds or rotation.