Spain’s prime minister, Pedro Sánchez, has ordered the country’s largest ever peacetime military deployment, announcing that another 5,000 troops will be drafted in to help deal with the aftermath of this week’s devastating floods, which have killed at least 211 people in eastern, southern and central regions.

Speaking after chairing a meeting of the flood crisis committee, Sánchez said the government was mobilising all the resources at its disposal to deal with the “terrible tragedy”, which stuck hardest in the eastern region of Valencia. He also acknowledged that much of the help still wasn’t getting through and called for unity and an end to political bickering and blame games.

“There are still dozens of people looking for their loved ones and hundreds of households mourning the loss of a relative, a friend or a neighbour,” he said in a televised address on Saturday morning. “I want to express our deepest love to them and assure them that the government of Spain and the entire state, at all its different administrative levels, is with all of them.”

Describing the torrential rains and floods as “the worst natural disaster in our country’s recent history” and the second deadliest European floods of the century, the prime minister announced a huge increase in the numbers of army and police personnel taking part in the relief effort.

In the first 48 hours of the crisis, he said, Spain had witnessed “the largest deployment of armed forces and police personnel that’s ever been seen in our country during peacetime. It has so far carried out 4,800 rescues and helped more than 30,000 people in their homes, on the roads, and in flooded industrial estates.”

Unfortunately, he said, much of the help was taking too long to reach blocked and flooded houses and garages and isolated villages.

“That is why the Spanish government is today sending 4,000 more personnel from the military emergencies unit to Valencia province,” said Sánchez. “Tomorrow, another 1,000 military personnel will arrive … I’ve also ordered the deployment of an amphibious navy boat that has operating theatres, helicopters and a fleet of vehicles that will arrive at Valencia port in the coming hours.”

The prime minister also said 5,000 more national police and civil guard officers would be sent to the region, taking total police numbers to 10,000.

“Our second priority is identifying and recovering the bodies of the dead and we need to do it quickly but with all the dignity and guarantees that the victims and their families deserve,” he said. “Over the past 48 hours, military and security personnel have inspected thousands of garages, riverbeds and roads, and recovered the bodies of 211 mortal victims.”

Specialist forensic personnel and mobile morgues were already in the disaster zone, he added, and would work “day and night; night and day for as long as it takes until all the victims have been located”.

Sanchez’s address came as thousands of volunteers turned up to Valencia’s City of Arts and Sciences centre, which has been transformed into the nerve centre of the clean-up operation. On Friday, the spontaneous mass arrival of volunteers complicated access for emergency workers to some areas, prompting authorities to devise a deployment plan.

The prime minister said power had been restored to 94% of affected homes, while phone lines were scheduled to be repaired over the weekend.

Sánchez also acknowledged the deep public anger over the handling of the emergency – many have questioned why the Valencian government did not send out an emergency alert until after 8pm on Tuesday – but called for unity.

“The situation we’re experiencing is tragic and dramatic,” he said. “We’re almost certainly talking about the worst flood our continent has seen so far this century. I’m aware that the response we’re mounting isn’t enough. I know that. And I know there are severe problems and shortages and that there are still collapsed services and towns buried by the mud where people are desperately looking for their relatives, and people who can’t get into their homes, and houses that have been buried or destroyed by mud. I know we have to do better and give it our all.”

He said there would be time later to look into what had gone wrong and to learn lessons “about the importance of our public services and how to reinforce them in the situations we’re living through as a consequence of climate change … But now we need to focus all our efforts on the colossal task we face and to forget our differences and put ideologies and disagreements to one side and act together.”

This week’s flash floods, caused by torrential rains that scientists have linked to the climate emergency, have inundated cities, towns and villages, sweeping away bridges, cars, trees and streetlights. The number of missing people remains unknown. Thousands more have no access to water or reliable food, while parts of the heaviest-hit areas remain inaccessible. The piles of vehicles and debris have trapped some residents in their homes while others are without electricity or stable phone service.

An orange weather warning remained in place on Saturday for Castellón, a province in Valencia, and for the a stretch of coast in Tarragona, a province in Catalonia.