President Xi Jinping has sent a message of sympathy to Spanish King Felipe VI over Spain's deadliest flash floods in decades, which have killed more than 200 people, including two Chinese citizens, and left many others missing.

In his message sent on Saturday, Xi said he was shocked to learn that severe rainstorms and floods had hit many parts in Spain, causing heavy casualties and loss of property.

The Chinese president, on behalf of the Chinese government and people, expressed deep condolences to the victims and sincere sympathy to the bereaved families and the injured.

Xi also said it is believed that under the leadership of the king and the Spanish government, the people in the flood-hit areas will overcome the disaster and rebuild their homes at an early date.

Almost all the deaths have been in the eastern Valencia region, where thousands of security and emergency services personnel frantically cleared debris and mud in search of bodies.

The Spanish government was deploying 10,000 more troops and police officers to the Valencia region, where hopes of finding survivors ebbed after torrents of muddy water submerged towns and wrecked infrastructure.

Spanish media reported that King Felipe VI and Queen Letizia visited the Valencia area on Sunday, accompanied by Prime Minister Pedro Sanchez.

Describing the situation as "the worst natural disaster in the recent history of our country", Sanchez said it was the second-deadliest flood in Europe this century.

Sanchez said the government had accepted the Valencia region leader's request for 5,000 more troops and informed him of a further deployment of 5,000 police officers and civil guards.

Spain was carrying out its largest deployment of military and security forces personnel in peacetime, he added.

Valencia's regional authorities said on Saturday night that the total number of deaths in the region was 211, plus two from Castilla La Mancha and one in Andalusia, Reuters reported.

The floods have killed two Chinese citizens and left two others missing, the Chinese embassy in Spain confirmed on Saturday.

Restoring order and distributing aid to destroyed towns and villages, some of which have no food, water and power supplies since Tuesday's torrent, is a priority.

Sanchez said that electricity had been restored to 94 percent of homes affected by power outages, and that around half of the cut-off telephone lines had been repaired.

Susana Camarero, deputy head of the Valencia region, said that people in some areas were "overwhelmed" by the show of solidarity and the food aid that they had received.

Ordinary citizens carrying food, water and cleaning equipment continued their grassroots initiative to assist the recovery on Saturday. Around 1,000 had set off from the Mediterranean coastal city of Valencia toward nearby towns laid waste by the floods, Agence France-Presse reported.

Thousands of volunteers were helping to clear away the thick layers of mud and debris that still covered houses, streets and roads, all while facing power and water cuts as well as shortages of some basic goods. Inside some of the vehicles that floodwaters had washed into piles or slammed into buildings, there were still bodies awaiting identification.

Authorities have urged people to stay at home to avoid congestion on the roads, which would hamper the emergency services work.

Regional leader Carlos Mazon laid out a series of proposals on Saturday to help his region recover, ranging from infrastructure repair to economic support.

Scientists warn that climate change driven by human activity is increasing the ferocity, length and frequency of such extreme weather events.

Spain's national weather service said that in the hard-hit locality of Chiva, it rained more in eight hours than it had in the preceding 20 months, and it called the deluge "extraordinary".

The flooding came after Spain had battled with prolonged droughts in 2022 and 2023. Experts have said that drought and flood cycles are increasing with climate change.