The European country is reeling from the October 29 disaster that has killed 227 people and sparked widespread fury at elected leaders for their perceived mishandling of the crisis.

That outrage boiled over in the ground-zero town of Paiporta in the eastern Valencia region when King Felipe VI and Queen Letizia visited on November 3, in extraordinary scenes that stunned the world.

Furious residents chanting "murderers" pelted them with mud and projectiles as they struggled to wade through the crowds, while Prime Minister Pedro Sanchez was hastily evacuated.

But crowds in the devastated Valencia region town of Chiva applauded and shouted "long live the king!" upon their highly anticipated arrival on Tuesday, AFP journalists witnessed.

Felipe and Letizia embraced residents and stopped for conversations and selfies as they toured streets cleared of mud and with their shops reopened.

The king wrote a message in Chiva town hall expressing the couple's "great affection, love and all our support and solidarity".

The same warm atmosphere greeted them in the nearby town of Utiel, where they visited destroyed neighbourhoods and spoke with affected students and farmers.

"I am not a monarchist... but I respect them because they are people who have never messed with anyone," Pascual Gimeno, a 58-year-old waste management worker, told AFP in Chiva.

The visit "has made many people happy."

The palace had maintained the utmost secrecy about the itinerary of the visit beforehand in the wake of the Paiporta unrest.

- Monarchy 'strengthened' -

Felipe and Letizia were keeping a promise to return to the region and console survivors, said Vicente Garrido, professor of constitutional law at the University of Valencia.

Whereas Sanchez and the Valencia region's under-fire leader Carlos Mazon left Paiporta early, the mud-spattered royal couple braved the popular anger to speak with victims.

Their willingness to travel and risk personal harm earlier this month "strengthens the image" of the monarchy, Garrido told AFP.

Popular ire has instead targeted elected politicians, particularly Mazon because the regions manage the response to natural disasters in Spain's decentralised state.

"What they did in Paiporta, I think it is an aberration," said Maria Victoria Sanchez, a 75-year-old Chiva resident.

The monarchs "aren't to be blamed for anything, here it's the politicians' fault", she told AFP.

"Mazon, if you had any shame you would be at home, murderer!" shouted one man in Chiva.

Local authorities in many cases warned residents of the impending catastrophe too late and stricken towns depended on volunteers for essential supplies for days in the absence of the state.

The conservative Mazon admitted "mistakes" and apologised in the regional parliament last week but refused to resign and vowed to lead Valencia's gigantic reconstruction effort.

The regional government on Tuesday appointed a retired high-ranking army officer to a new post in charge of rebuilding Valencia.

Sanchez is due to appear in parliament this month to explain the left-wing central government's handling of the floods.