Emergency sirens were heard across Tokyo, Japan, after torrential downpours struck the country, warning residents of flooding risks.

Footage shows storm clouds looming over city buildings, with alarms echoing in the background on July 10.

The filmer said: 'Is this what they call a rain column? Torrential downpour, hardcore!'

Heavy rainfall hit Tokyo on Thursday evening during rush hour, prompting the Japan Meteorological Agency to advise residents to remain alert for potential flooding, heavy rain, and lightning activity.

The agency reported around 120 millimetres of rain in Suginami Ward and roughly 100 millimetres in Setagaya Ward around 7 pm.

Similar weather alerts were issued in the neighbouring prefectures of Saitama, Kanagawa, Yamanashi, Gunma, and Nagano.

Authorities added: 'Cumulonimbus clouds have developed in some places, causing torrential rain and lightning.'

Forecasts predict up to 150 millimetres of rainfall in the Kanto region, including Tokyo, and approximately 100 millimetres in the Koshin region, covering Yamanashi and Nagano prefectures, over the 24 hours through 6 pm Friday.

In Japan, emergency sirens are commonly used to alert the public during natural disasters such as heavy rain, flooding, earthquakes, and landslides. These notices are part of the country's disaster prevention system and are broadcast through outdoor speakers by local governments.

The system is designed to provide quick, widespread alerts to help keep communities safe.