At least 126 people died in the storm that hit the central Philippines at the end of December, most of them in landslides.
The previous toll was 68 people killed by a storm that hit the islands east and archipelago on December 29, causing flooding.
More than 100 people have died in the mountainous Bicol region to southeastern Manila, officials at the Department of Natural Disaster Management said.
Many people did not take the necessary precautions in the archipelago of extreme climatic events as the authorities did not classify the storm as a hurricane, and many did not seem to hesitate to leave their homes during the Christmas and New Year.
"In just two days, the equivalent of more than a month of rain fell on the Bicol region from Osman," spokesman Edgar Posadas told AFP.
"Searches are continuing, but mudslides and soil instability are a challenge," he said, adding that 26 people were missing.
The storm displaced more than 152,000 people, while at least 75 were injured.
The Philippines strikes an annual average of 20 hurricanes and storms, which kill hundreds of people and cause extreme poverty that affects millions almost permanently.
The most powerful of these storms was Hurricane Hayyan, which killed more than 7,360 people dead and missing across the Philippines in 2013.
