The storm affected more than 900,000 in the Philippines before exiting at about 8am on Tuesday. It is likely to further intensify over the sea and reach its peak within 24 hours, the Philippine weather bureau said.
The northern area of Vietnam’s Central Highlands, home to the country’s coffee producers, is forecast to receive as much as 200 millimetres of rain from Tuesday evening, according to a local meteorological centre.
Typhoon Molave struck the Philippines Sunday, inundating low-lying villages and farmlands, knocking down power lines and destroying hundreds of houses as it crossed the archipelago.
Thousands are still sheltering in evacuation centres.
The National Disaster Risk Reduction and Management Council (NDRRMC) warned the number of casualties could rise as regional authorities assess the damage in their areas.
At least three of the deaths were drownings, NDRRMC spokesman Mark Timbal said.
Among them was a woman who was swept away by surging currents as she tried to cross a river, Rizajoy Hernandez of the Civil Defense office in the Central Visayas told AFP.
Twelve people, mostly fishermen, have been reported missing after being caught in rough seas.
More than 70,000 people remain in over 800 evacuation centres.
The Philippines is hit by an average of 20 storms and typhoons every year, making them a dangerous and disruptive part of life in the country.
Many of the storms are deadly, and they typically wipe out harvests, homes and infrastructure, keeping millions of people perennially poor.
The country's deadliest typhoon on record was Super Typhoon Haiyan, which left more than 7,300 people dead or missing in 2013.