Vigilante groups patrol Spain's flood-hit Paiporta by night

Vigilante groups, angry at authorities' response to Spain's worst flood disaster in decades, have taken to the streets of the Valencian suburb of Paiporta to prevent what they say are widespread robberies and looting after dark.

The informally organised groups of stick-wielding locals are patrolling one of the worst-affected areas, where more than 60 out of at least 217 victims of the disaster died.

Martin, 19, told Reuters that he and his friends were taking the law into their own hands because they believed police were not carrying out their duty to maintain public safety.

"We're patrolling because we don't want our neighbours to feel the insecurity they've been feeling the past few days due to various robberies," he said. "People have already lost enough."

Public anger has mounted over what residents say was a slow and insufficient response by authorities, which led to King Felipe and Prime Minister Pedro Sanchez being pelted with mud during their visit on Sunday.

Six days after the torrential rains, the street lights on most of Paiporta's rubble-strewn streets do not work. Foul-smelling, stagnant water remains ankle-deep, concealing hazards such as uncovered manholes or damaged cables.

Speaking at a press conference in Madrid on Tuesday, Sanchez paid tribute to the work of the national police and civil guard.

"I remember at the first moments of this emergency there was talk of looting," Sanchez said. "Today fortunately we are observing that this looting is falling to absolutely marginal figures. More than 170 people have been detained."

National police have shared footage of seized items, mostly sportswear such as high-end running shoes.

Spain has now sent almost 15,000 police and armed forces personnel from all over Spain to the Valencia region to help clear up after the disaster.

A police spokesperson told Reuters the director general of Spain's national police force, Francisco Pardo Piquero, would give a press conference at the government headquarters later on Tuesday in which he would address looting, among other topics.

Some of the volunteers on patrols wore T-shirts emblazoned with far-right symbols or said they belonged to "patriotic" groups. Others denied having extremist ideologies and accused the media of manipulating public opinion against them.

Reuters did not witness any encounters between alleged criminals and the vigilante groups.

"We're carrying tools for safety and wearing head torches so that when they see us coming, with a bit of luck they'll run away," said Zaida Puerta, 21, holding a hoe.