Cyclone Mekunu intensifies as it advances on Oman
"Latest observations show that tropical cyclone Mekunu has intensified to category 2," with high wind speeds, Oman's Directorate General of Meteorology said on Twitter.
The Gulf state's early warning centre said that the eye of the cyclone was just 180 kilometres (112 miles) away from Salalah, the main city in Dhofar province.
It expected that Mekunu will make landfall in the early hours of the afternoon.
Several cities in Dhofar were lashed by heavy rain in the early hours of Friday as the centre of the cyclone approached the coast, it added in a statement carried by the official Oman news agency.
Oman on Thursday placed police and army on alert and closed schools until Monday in preparation for the cyclone.
State-run television in Oman said authorities evacuated hundreds of residents from a small island off the southern city of Salalah, capital of Dhofar province.
Oman's civil aviation authority has announced that Salalah airport would be closed for 24 hours from midnight (2000 GMT Thursday).
At least 17 people were missing after Mekunu hit Yemen's Socotra island on Thursday, causing severe flooding and damage.
The government declared Socotra a "disaster province".
The Yemeni high relief agency met with international humanitarian organisations in Aden late Thursday to discuss the situation on the island, the Saba news agency reported.
It was decided to set up 11 relief centres in Socotra to provide shelter for people who were forced to evacuate their homes.
The meeting also discussed taking the necessary measures to provide aid to people in three provinces in southeast Yemen expected to be hit by the cyclone.