Relief aid started to be flown in to Yemen on Wednesday as a rare tropical cyclone eased into a depression after wreaking havoc in parts of the war-torn country.

Cyclone Chapala weakened after making landfall Tuesday in mainland Yemen, triggering heavy flash floods after severely striking the country's Arabian Sea island of Socotra.

A fisherman drowned on Wednesday as the storm generated high waves off the southern port city of Aden and flooded its seafront Abyan Road, his union said.

Three military planes sent by Oman landed in Socotra with 54 tonnes of food and medicine, Saba state news agency reported, adding that six more planes from the sultanate were expected by Thursday.

The United Arab Emirates also dispatched a plane loaded with 20 tonnes of relief aid to Socotra, the Emirati official news agency WAM said.

The shipment included tents and blankets, in addition to food.

More than 200 people were injured and dozens of houses and hamlets severely damaged or washed away when Chapala hit Socotra, according to Salem Zaher, mayor of the island's main district Hadibo.

Socotra is located 350 kilometres (210 miles) off the Yemeni mainland.

The UN's Office for the Coordination of Humanitarian Affairs has cited reports of three fatalities and 34 injured in Yemen due to the cyclone.

But the government insisted late Tuesday that Chapala had not caused any deaths.

The World Health Organization has said it delivered trauma kits for 1,000 patients in coastal Mukalla, the provincial capital of Hadramawt in southeast Yemen.

It said it was also providing fuel for hospitals and ambulances in Mukalla, most of which has been under Al-Qaeda control since April.

The UN said Tuesday that at least 1.1 million people, mainly in the provinces of Hadramawt and Shabwa were expected to be affected by Chapala.

Initial reports suggested over 40,000 people had been displaced or temporarily evacuated from coastal areas, it said, and at least 450 homes damaged or destroyed.