Torrential rain, flooding in Seoul kill seven

Authorities warned of more rain to come even as emergency workers tried to clear the hulks of flooded cars, which AFP reporters saw strewn across major intersections throughout the city.

Dramatic images shared on social media late Monday showed people wading through waist-deep water, metro stations overflowing, and cars half-submerged in Seoul's posh Gangnam district, which was particularly hard-hit when torrential rain battered the city.

The downpour that began Monday is the heaviest rainfall in South Korea in 80 years, according to Seoul's Yonhap News Agency.

"At least seven people died in the Seoul metropolitan area, while seven others are missing, due to heavy rain as of 7:30 this morning," an official at Seoul's Interior ministry said

Local reports said three people living in a banjiha -- cramped basement flats of the kind made famous in Bong Joon-ho's Oscar-winning "Parasite" -- including a teenager, died as their apartment was inundated by floodwaters.

Gangnam, a wealthy district in southern Seoul -- which was featured in Psy's 2012 K-pop hit "Gangnam Style" -- received 326.5 millimetres of rainfall on Monday, data from the Korea Meteorological Administration showed.

Yonhap said the downpours were the heaviest recorded since 1942.

President Yoon Suk-yeol ordered government officials to evacuate residents from high-risk areas and encouraged businesses to allow employees flexible commuting hours on Tuesday morning.

"Record-breaking torrential downpours in the central region since yesterday have caused a lot of damage, including unfortunate casualties," Yoon said on Facebook Tuesday, adding the government would provide "prompt recovery and damage support".

Neighbourhoods close to the presidential residence in southern Seoul were affected, images of the flooding posted on social media showed.