VALENCIA, Spain (AP) — Thousands of Spaniards marched in the eastern city of Valencia on Saturday to demand the resignation of the regional president in charge of the emergency response to last week’s catastrophic floods that left more than 200 dead and others missing. Some protestors clashed with riot police in front of Valencia’s city hall, where the protestors started their march to the seat of the regional government. Police used batons to beat them back.

Regional leader Carlos Mazón is under immense pressure after his administration failed to issue flood alerts to citizens’ cellphones until on the night of Oct. 29. Many marchers held up homemade signs or chanted “Mazón Resign!” Others carried signs with messages like “You Killed Us!” Mazón, of the conservative Popular Party, is also being criticized for what people perceive as the slow and chaotic response to the natural disaster.

Thousands of volunteers were the in many of the hardest hit areas on Valencia’s southern outskirts. It took days for officials to mobilize the thousands of police reinforcements and soldiers that the regional government asked central authorities to send in. In Spain, regional governments are charged with handling civil protection and can ask the national government in Madrid, led by the Socialists, for extra resources.

Mazón has defended his handling of the crisis saying that its magnitude was unforeseeable and that his administration didn’t receive sufficient warnin.