MANILA (Reuters) - Philippine President Joseph Estrada declared a ‘state of calamity‘ in four provinces on Monday after flash floods killed 20 people and displaced more than 110,000 families in the Caraga region on Mindanao island. The rains had not let up, although floods had started to recede in some parts of this southern region, officials said. Landslides and collapsed bridges isolated some towns, and wide areas of Butuan City, the largest in the region, were without power, they added. The National Disaster Coordinating Council said damage totalled 123 million pesos ($3.2 million) in the four rice and corn-growing provinces that make up the region — Agusan del Norte, Agusan del Sur, Surigao del Norte and Surigao del Sur. "This is the effect of continuous rain since February 4," the operations director of the National Disaster Coordinating Council, Frank Castillo, told Reuters. "On February 4, we had a 24-hour downpour. It was the worst flooding (in Agusan del Sur) since 1981," Dante Villacrusis, provincial administrator said by telephone. Caraga region Senior Police Superintendent Fritz Quinola said nine people drowned in Agusan del Sur while two died of diarrhoea caused by infected water. He said five people drowned, two were electrocuted and two children died when buried under landslides in Agusan del Norte, where officials reported floodwaters up to three metres (10 ft) deep. Three people were also missing and 16 injured. At least 111,000 families were forced to flee to higher ground and some areas were still under water, officials said. Defence Secretary Orlando Mercado blamed a lack of forest cover for the flash floods. "Caraga is a region that has been the centre of logging activity in the past," he told a news conference. "These are the consequences of the abuse of our forest resources." Mercado said other deforested areas might suffer the same problems, which he also linked to the current La Nina weather pattern — the weather phenomenon associated with strong rains and floods in southeast Asia.