A woman has been taken to hospital with minor injuries after the blasts caused "mayhem" on the Gold Coast.
An investigation has been launched but authorities on Monday believed the explosions on the Surfers Paradise tourist strip may have been caused by an electrical fault.
Up to three blasts occurred around 5pm on Sunday, with a woman in her 20s falling into a manhole on the popular Cavill Avenue.
Online video showed the manhole acting like a trap door for the unfortunate woman following one of the underground explosions.
"You are just walking along minding your own business and all of a sudden this happens," Superintendent Peter Miles told reporters on Monday.
"Given the cycle of world events you wouldn't know what is going on.
"It would have been mayhem those first few minutes I would imagine."
The woman was helped by bystanders before paramedics arrived and she was treated at hospital.
"I believe she is okay. They (injuries) were very minor in nature but when you think about what could have happened it's a success story," Supt Miles said.
"(It is a) miracle it was not more severe than that.
"I imagine it wouldn't have taken too much especially if there were accelerants around, it could have easily turned into a catastrophic event."
The explosion sparked an exclusion zone in the busy area, with police asking people to avoid Cavill and Elkhorn Avenue, The Esplanade, and Surfers Paradise Boulevard.
UPDATE: The Public Safety Preservation Act (PSPA) for Surfers Paradise has been revoked.— Queensland Police (@QldPolice) Reduced road closures remain in place with limited pedestrian access on Cavill Avenue and Orchid Avenue.https://t.co/4JzkMimQs7 pic.twitter.com/wQsjtDGnjmDecember 8, 2024
Power was also cut off in the area as a precaution before the exclusion zone was lifted about 90 minutes later.
Engineers were assessing the damage on Monday.
"Energex has come through and believe it was an electrical fault of some sort," Supt Miles said.
"But there doesn't appear to be any further risk to the community,"
A couple having dinner when the explosion rocked the tourist strip said they weren't allowed home for hours.
"We were sitting in a restaurant ... and we heard a small explosion," Beck and Dave Morrison told the Nine Network.
"We just ordered dinner and then we heard another really loud explosion.
"Then the police cars and the fire trucks were here and we were told to evacuate immediately."
Supt Miles believed the underground blasts were a first for the popular tourist destination.
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