Ten people have died after tropical cyclone Shaheen battered parts of Iran and Oman.
The storm arrived in the area on Sunday, with winds between 120 and 150 km/h (75-93 mph) as its eye crossed land, reports BBC.
Thousands have been evacuated from coastal areas in Oman. Streets in the capital, Muscat, have been submerged.
Shaheen was later downgraded to a tropical storm after it hit land, a local meteorology service said.
In Iran, authorities said six people - thought to be fishermen - were killed in a port in the south-eastern province of Sistan-Baluchestan.
The country's official media said infrastructure including electrical facilities and roads were damaged.
Even before the cyclone made landfall in Oman, four people, including a child, had already died due to flooding.
Images from Muscat show cars submerged in water. Authorities in the capital ordered roads to only be used for emergency journeys.
Oman's state news agency says the armed forces are rescuing people who have been trapped by the floodwater. They are also restoring damaged roads to get aid into the areas that need it.
Flights to and from Muscat were suspended and residents in coastal areas were urged to evacuate.
A cricket match between Oman and Scotland was abandoned due to the cyclone.
Authorities cut off the power supply in al-Qurm, east of Muscat, to avoid any incidents, and some 2,700 people were placed in emergency shelters.
Parts of the neighbouring United Arab Emirates are now on standby as the weather system moves west.
Residents of al-Ain, on the border with Oman, have been told to work remotely on Monday and avoid leaving home except for emergencies.