HONG KONG —  Parts of Hong Kong were brought to a standstill by flooding caused by heavy rains on Tuesday, after the highest-tier rainstorm warning was issued for the fourth time in eight days.

The financial hub has suspended school classes and opened temporary shelters, and some hospital services have also been affected.

The city’s weather observatory hoisted the “black” rainstorm warning—meaning downpours exceeding 70 millimetres in an hour—late on Monday and again in pre-dawn hours.

This morning the city’s weather observatory warned there could be “severe flooding”, adding that hourly rainfall had already exceeded or was expected to exceed 100 millimetres in some regions.

Images circulated on social media showed cars nearly submerged at an outdoor parking lot in the eastern Tseung Kwan O district.

Emergency room service at the Queen Mary Hospital was affected due to “severe flooding” on some roads, health authorities said.

Public transport slowed to a crawl in some districts and a handful of subway station exits have been closed, according to local media.