Los Angeles (AFP) - A typhoon that slammed into Guam, knocking out power and flooding buildings with a powerful storm surge, was moving away Thursday – leaving residents of the US Pacific Ocean territory to survey the damage.

Governor Lou Leon Guerrero was set to venture out when conditions allow to see what damage has been wrought on the island, a key US military outpost and home to 170,000 people.

The governor and civil defence groups will look for “any major damages or blocked roadways in the wake of Typhoon Mawar,” a statement said Thursday.

“As Guam received the full brunt of the typhoon overnight, the assessment will help determine what damages may have occurred.”

Mawar brought winds of up to 225 kilometers (140 miles) an hour, the US National Weather Service reported, generating waves nine meters (30 feet) high.

There were no reported deaths or injuries.

At one of the island’s many hotels, the 30-floor Dusit Thani Guam Resort housing about 300 guests, desk clerk Casey Hattori said the lobby was inundated with a foot of water, even with the front door barricaded with boards and bags of concrete. Outside, trees snapped in howling wind.

“I can hear the walls shaking. The wind is super strong. I can hear it whistling as it comes through the cracks of the doors,” Hattori told AFP.

Fearful tourists were evacuated from flooded rooms to a sixth floor ballroom, she said.

Images on social media showed the impact of winds that had uprooted trees, swept away vehicles and dislodged roofs, throwing debris everywhere.

Tens of thousands of homes were without power Thursday, the Guam Power Authority said, but noted that a total blackout had been avoided.

“We are working hard to maintain the last remaining customers through the storm, which contributes to quicker recovery after the winds die down later tonight or in the early morning hours,” the agency said, according to the Pacific Daily News.

The NWS said Mawar was now a Super Typhoon, and forecasting models suggested it was heading towards Taiwan or the Philippines.

“As sunlight is starting to peek, we are waking up to a rather disturbing scene out there across Guam,” one forecaster said during a morning update Thursday.

“We are looking out our door and what used to be a jungle looks like toothpicks. It looks like a scene from the movie ‘Twister,’ with trees just thrashed apart.”

The agency said Guam remained under a typhoon warning, with destructive gusts and heavy surf expected.

Ocean conditions are still treacherous, even for large vessels, it said.

“Residents are urged to stay off the roads and remain in safe, hardened shelters” for now, emergency officials warned.

In Washington, the White House said President Joe Biden had been briefed on the situation.

“The White House is in close contact with the government of Guam and has offered as much support as needed,” a spokeswoman said.

About 21,700 US military personnel and their families are based on Guam, which routinely hosts nuclear attack submarines and long-range bombers.

The territory is also home to key electronic listening posts, and the US bases have some of the Pacific region’s most significant ammunition and fuel storage facilities.

Lieutenant Commander Katie Koenig, spokesperson for Joint Region Marianas said military aircraft and ships departed before the destructive winds began or were sheltered in hangars, “except for one vessel which remains in port due to an inoperable engine.”

Koenig added that all military and civilian personnel were instructed to take shelter.

“Our service members throughout the Marianas routinely exercise natural disaster response and are ready and postured to respond… once the ‘all clear’ order is given,” she said.