Cyclone Mekunu was downgraded further to a deep depression on Saturday, a day after lashing the southern coast of Oman and killing at least two people, authorities said.
Civil defence officials said a man and a 12-year-old girl were killed, while three Asian nationals were missing after the cyclone hit Oman's Dhofar and Al-Wusta provinces.
Oman police earlier reported that the man died after floods swept him away with his car near Salalah, Oman's second-largest city, while the girl died when a gust of wind smashed her into a wall.
Mekunu, which has wreaked havoc in Yemen's Socotra island killing at least seven people, was heading northwest to Saudi Arabia, Oman's directorate of meteorology said.