Flash flood swepts through a restaurant while school teachers were eating their lunch in Thailand.

Footage shows the ankle-deep deluge gushing under tables in Khon Kaen province in the north of the country on August 1.

The teachers had already ordered their food when the water started pouring in from a rainstorm outside - so they just continued with their meal of stir-fried vegetables, beef, rice and papaya salad.

Onlooker Prem Primchanok said: 'The restaurant is right next to a waterfall. This say there was very heavy rain, so the stream overflowed and spilled into the restaurant.'

Thailand and other countries in Southeast Asia such as Malaysia, Indonesia, Myanmar, and the Philippines are at the start of their tropical monsoon rainy season, which lasts until late November.

Soaring temperatures reaching 35 degrees Celsius are often followed by powerful tropical storms with thunder, lightning, rain and flash floods which cause rivers to flow faster and become dangerous.