A stretch of Lai Chi Kok Road was closed on Sunday morning after an overnight water burst caused extensive flooding.
The main burst shortly after midnight, sending large amounts of water into the road, and dramatic pictures widely shared online showed a taxi submerged in the water.
The Transport Department said all lanes of the Mong Kok-bound stretch near Butterly Valley Road remained closed as of 9am on Sunday.
Bus routes 40, 268X, 63X, 904, 2A, 6C, 2X, 32, 42, 30, 50 and 795X have all been diverted