At least 158 people have died in Spain's worst flooding disaster in generations as rescuers battle odds to find survivors.

On Thursday more than 1,200 workers, aided by drones, were deployed to the rescue mission as rains continued to threaten parts of the country.

"Right now the most important thing is to save as many lives as possible," Prime Minister Pedro Sánchez told victims in a visit to affected communities.

But in some of the towns worst- hit in Tuesday night's floods, people were left to the task of recovering bodies from the mud and wreckage.

At least 155 deaths were recorded in Valencia, while another two have been recorded in Castilla-La Mancha to the province's west, and another, a British man, in Andalusia.

In the town of Paiporta, Valencia where a river burst its banks, at least 40 deaths have been recorded so far.

"We all know someone who has died," said pharmacist Miguel Guerrilla, standing outside his chemist shop which has been covered in thick mud.

"It's a nightmare."

Here is a link to a video update by Joel Forster, the head of Evangelical Focus in Spain: https://www.instagram.com/reel/DBv9hc7MhNw/?igsh=MTV3cHFlOXV0ZXNtcw==