Hong Kong was hit Friday by the worst downpour in over 140 years that killed at least two people and injured 100 others, local media reported Friday.

Local authorities spoke of "extreme conditions" in a statement Friday. Schools remained closed and businesses were told to give their employees the day off.

The Hong Kong Observatory registered a new rainfall record for part of the city overnight. At the observatory's headquarters, 158.1 millimetres of rain was recorded in one hour. This is the highest value since records began in 1884.

On Thursday night, the meteorological observatory issued a "black warning," meaning that "heavy rain has fallen or is expected to fall generally over Hong Kong, exceeding 70 millimeters in an hour, and is likely to continue."

'Rain of the century'

The South China Morning Post reported roads that turned into raging rivers while bourse operator HKEX halted the morning session Friday.

Images of flooded underground car parks and underground railway stations were shared on social media. There were also landslides.

Hong Kong Chief Executive John Lee Ka-chiu spoke on Facebook of a "rain of the century" and called on the population to avoid going outside if possible.

Extreme rainfall also occurred in the neighboring Chinese metropolis of Shenzhen.

Just last weekend, Typhoon Saola hit the region with heavy rain and gale-force winds. Unlike with the current rainstorm, however, the authorities had warned of Saola well in advance.