A sinkhole in a major road in Fukuoka, Japan, was repaired within 48 hours, but the road was reopened five days later after the necessary safety tests were carried out.

Parts of a main street collapsed in the heart of a major city in southern Japan on Tuesday last week, creating a massive sinkhole and cutting off power, water and gas supplies to parts of the city.

The hole - 30 metres by 27 metres, and 15 metres deep, was repaired by Thursday, but the road was only reopened today after all the tests were carried out.

Authorities said no injuries were reported from the pre-sunrise collapse in downtown Fukuoka, which created a sinkhole more than half the size of an Olympic pool in the middle of the business district.

The cause of the collapse is under investigation, Fukuoka officials said, but they linked it to ongoing subway construction nearby. A smaller sinkhole occurred in Fukuoka in 2014 at another location of the subway construction.

Fukuoka, a city of more than 1.5 million people, is about 1,000 kilometers southwest of Tokyo. The massive cave-in appeared in the city's bustling Hakata district, a major business and entertainment center, with muddy underground water flowing into the hole.

The incident prompted the evacuation of some residents in nearby buildings. Officials were concerned that further erosion inside the sinkhole could prompt nearby structures to collapse.