VALENCIA -- Tens of thousands of people demonstrated in the eastern Spanish city of Valencia on Saturday over regional authorities' handling of devastating floods that killed more than 220 people in one of Europe's worst natural disasters for decades.

In the latest demonstration over the floods, protesters filled the centre of Valencia demanding the resignation of regional government leader Carlos Mazon and chanting "Killers!".

"Our hands are stained with mud, yours with blood," read one banner. Some demonstrators dumped dirty boots outside the government building while others plastered it with mud.

Residents in stricken areas accuse Mazon of issuing an alert too late, at 8 p.m. on Oct. 29, well after water was already pouring into many nearby towns and villages.

The Valencian leader has said he would have issued an earlier alarm earlier if authorities had been notified of the seriousness of the situation by an official water monitoring body. Mazon did not respond to Reuters' requests for comment.

"We want to show our indignation and anger over the poor management of this disaster which has affected so many people," said Anna Oliver, president of Accio Cultural del Pais Valenciano, one of about 30 groups that organised the protest.

Though the demonstration was largely peaceful, police charged stone-throwing protesters at one point and objects hurled at the city council building caused minor damage.

Following days of storm warnings from the national weather service from Oct. 25 onward, some municipalities and local bodies raised the alarm much earlier than the regional government.

For example, Valencia University told its staff on Oct. 28 not to come to work. Several town halls suspended activities, shut down public facilities and told people to stay home.

Weather service AEMET raised its threat level for heavy rains in the area to a red alert at 7:36 a.m. on Oct. 29.

Nearly 80 people are still missing in what is the most deadly deluge in a single European country since floods in Portugal in 1967 killed around 500.