7 more people were killed as heavy winds and rain swept through the country after Cyclone Shaheen in Oman made landfall.
The national emergency committee via twitter
Four people had been killed on Sunday including a child.
Latest data showed that the storm had subsided, the civil aviation authority said on Monday, warning that scattered rainfall was still expected.
It urged citizens to be careful crossing valleys and avoid low lying areas.
When its eye crossed land, Cyclone Shaheen in Oman was carrying winds of between 120 and 150 km per hour (75-93 mph), Omani authorities said. It was throwing up waves of up to 10 metres (32 feet)
Video footage from Omani broadcasters showed vehicles submerged as people tried to make their way through muddy brown floodwater. State TV showed people in flooded areas being rescued by helicopter.
Up to 500 cm (20 inches) of rain was expected in some areas, raising the risk of flash floods.
Cyclones steadily lose their power over land and Shaheen was downgraded to a tropical storm after it cleared the ocean, the meteorology service said on Twitter.