A typhoon was heading straight for the main Philippine island of Luzon on Friday, prompting storm alerts in nearly 20 provinces and placing army and police units on standby.
With center winds of 130 kph, Typhoon Koppu was about 585 km east of northeast Aurora province and moving west at 15 kph.
Tropical Storm Risk forecast it would gain strength overnight.
"We have placed military and emergency workers on alert," Alexander Pama, executive director of the National Disaster Risk Reduction and Management Council, said.
President Benigno Aquino appealed on television to people not to panic and to make preparations. The last time Aquino made a televised appeal was in 2013, the day before super typhoon Haiyan struck the central Philippines, killing more than 6,300 people and leaving millions homeless.
An average of 20 typhoons hit the Philippines every year.