At least eight people have died and 14 others have been injured as flooding caused by torrential rain hit parts of South Korea's capital Seoul.

Heavy downpours on Monday night submerged roads, flooded metro stations and caused blackouts across the city and neighbouring provinces.

Some areas received the highest rate of rainfall in 80 years, Korea's meteorological agency said.

Weather officials said the rain was likely to continue over several days.

Images showed floodwater gushing down the steps of metro staircases, parked cars submerged up to their windows and people making their way across streets in knee-high water.

Local reports said three victims were living in a semi-basement apartment known as a banjiha.

Rescue officials said they were unable to access the apartment as floodwaters had risen to waist-high levels on the street.

The windows belong to a basement apartment where three people, trapped by the water, drowned last night - two sisters in their 40s and one of their 13-year-old daughters. This morning it is still surrounded by floodwater and debris.

Sun-woo has lived in the flat above the family for 10 years. By the time he arrived home at 8pm, their home was submerged.

"I feel devastated about this tragedy," he said. "If I'd come home earlier perhaps, I could have saved them. I have a lot of regrets."

He said the family who had died had lived there for 10 years, and that their older sister had learning difficulties.

The home is almost identical to the apartment featured in the Oscar-winning film Parasite. The real life events here evoke the opening scene, in which the leading family tries desperately to funnel the water out of their home during a torrential downpour - only this outcome is far worse.

That South Korea's President Yoon visited the apartment earlier shows these deaths are significant.

They are a reminder that away from the glitzy towers of upmarket Gangnam, where much much of the damage was done, live hundreds of Koreans in these subterranean apartments that are not fit for purpose.

Meanwhile, Seoul's Dongjak district recorded more than 141.5 mm of rain per hour - the highest rate since 1942, according to Korea's Meteorological Administration (KMA).

The other victims included a person who was electrocuted, one person was found under the wreckage of a bus stop and another died in a landslide. At least 14 were injured and six others reported missing.

At least 163 people in Seoul have been made homeless and have taken shelter in schools and public facilities, according to Yonhap.

The downpour also affected public transportation, as flooded railroads forced suspension of railway services in Seoul and Incheon.

South Korean president Yoon Suk-yeol ordered government officials to evacuate residents from high-risk areas, and urged businesses to grant employees flexible commuting hours on Tuesday morning.

The KMA continued to issue heavy rain warnings across Seoul and surrounding metropolitan areas, and said it expected rainfall for the central part of the country to continue at least until Wednesday.