Ibiza -- famed for its pristine beaches and wild nightlife -- closed the main motorway to the airport, where social media footage showed rainwater seeping into the terminal, and briefly halted all public transport.

All operations at Ibiza airport were halted for more than an hour while the runway was cleaned, with 24 of 295 flights cancelled, according to operator Aena.

On the neighbouring island of Mallorca, 19 of 942 planned flights were cancelled.

Vehicles were slowly ploughing through murky floodwater in Ibiza and neighbouring Formentera against a backdrop of a dark sky, thunder and lightning, with some drivers requiring rescue, according to videos on social media.

Reinforcements from the Spanish army's emergencies unit were being deployed from the mainland to aid water pumping tasks.

Ibiza, Formentera and Mallorca sent mass telephone alerts warning residents to avoid unnecessary travel and waterways.

A lightning strike left 576 users without power after hitting an electrical cable in Formentera, while around 300 other users were also affected across Menorca, Ibiza and Mallorca, the Balearic regional government said.

In the eastern Valencia region, authorities warned of further "intense rain and localised storms" from 08:00 pm (1800 GMT) and said 571 incidents had been reported there since the start of the weather warning earlier this week.

In the Valencian town of Carcaixent, the storm dumped 110 litres per square metre of rain in just one hour, rapidly flooding streets, regional weather monitor Avamet said.

In late September, huge downpours prompted localised flooding and the closure of beaches and schools in Ibiza and Valencia, reviving painful memories of last year's floods which killed more than 200 people.

Because a hotter atmosphere holds more water that evaporates from a rapidly warming Mediterranean Sea, climate change increases the risk and intensity of flooding from extreme rainfall in the region.

imm/yad

AENA