By Erik de Castro
BUTUAN CITY, Philippines, Jan 21 (Reuters) - Emergency workers evacuated thousands of people across the southern Philippines on Tuesday, including many already made homeless by a typhoon in November, after three days of rain flooded towns and farmland.
Hundreds of survivors of Typhoon Haiyan, one of the strongest storms ever to make landfall, were forced to flee by tropical depression "Agaton" after emergency shelters were damaged or destroyed on the eastern central island of Samar.
Tents collapsed under the weight of the rain and emergency plastic sheets have been torn away, humanitarian agency Oxfam said.
An average of 20 typhoons hit the Philippines every year with Haiyan slamming into central islands on Nov. 8, killing more than 6,100 and wiping out entire coastal communities in Leyte and Samar.
More than 200,000 people have been taken to shelters over the last three days as flood waters rose, but hundreds were still marooned on the roofs of their houses on Tuesday, said Eduardo del Rosario, executive director of the National Disaster Risk Reduction and Management Council.
Del Rosario said 42 people had been killed, 65 had been injured and damage to property and farms had reached 367 million pesos ($8.13 million).
"Our troops are trying to reach them and bring them to safer ground," del Rosario said.
Nenita Matuda, 45, and her children perched on their neighbours' roof as she watched the rampaging waters outside Butuan City in the north of Mindanao island.
"Thank God we are safe but we just lost our house," she told Reuters as she wiped tears from her eyes.
A state of calamity has been declared in Agusan del Norte and 15 other towns in the Davao del Norte, Surigao del Sur and Agusan del Sur areas of Mindanao even as weather bureau lifted alert levels as the storm weakened. ($1 = 45 pesos) (Reporting By Manuel Mogato; Editing by Nick Macfie)