The Tropical Cyclone Shaheen has been downgraded to a tropical storm in Oman, the state news agency reported on Sunday.
Its center has also made landfall and its wind speeds are estimated at 102-116 kilometers per hour.
When Shaheen's eye crossed land, it was carrying winds of between 120-150 kilometers per hour and throwing up waves of up to 10 meters, Oman's authorities said.
Electricity has been cut off to the state of Suwaiq as a precaution as it is witnessing torrential rains.
Shaheen has so far killed three people, two Asian workers and a child, with one person remaining missing, according to the state news agency.
Oman has cancelled all scheduled flights in and out of the country and suspended schools.
Video footage of the weather in Oman showed vehicles submerged as people tried to get around in muddy floodwater.
Oman's authorities set up dozens of relief centers and shelters in the governorates affected by Shaheen.