Authorities have partially reopened a stretch of road in Sham Shui Po that was hit by heavy subsidence, earlier than expected.

A section of Hai Tan Street was cordoned off after part of the carriageway plunged into a four-metre-deep hole that measured about eight by 12 metres.

Late on Sunday evening, the fast lane of Hai Tan Street, between Yen Chow Street and Kweilin Street, was reopened following temporary repairs.

"Vehicles are still prohibited from making a left turn from Kweilin Street into Hai Tan Street. Affected bus routes have resumed their original routeings," the Transport Department said.

Authorities had earlier expected to complete repairs by midnight and reopen the lane before 6 am on Monday.

The government said permanent repair works would be carried out on the slow lane, which is expected to reopen to traffic before Wednesday’s rush hour.

Officials would then begin permanent repairs for the fast lane that would be completed on June 7.