Taiwan issued a warning on Monday for large waves, torrential rain and high winds as Mitag rumbled south of its coastline.
"Waves in the oceans around Taiwan are extremely big," the bureau said in a statement. "Ocean travellers and boats working at sea should be especially careful."
Mitag was not expected to make landfall as a typhoon in Taiwan, but it might come ashore as a lower-level tropical storm in Kaohsiung, Taiwan's second largest city, on Tuesday, according to British typhoon tracking Web site Tropical Storm Risk (www.tropicalstormrisk.com/).
INUNDATED FARMS
In the central province of Albay, where the sun was shining on Monday, tens of thousands of people were allowed to leave makeshift shelters in churches, schools and town halls as Mitag headed out to sea.
Disaster officials said Mitag flooded wide areas in the northern and central Philippines, destroying more than 100 million pesos (1.1 million pounds) worth of agricultural production, half of them rice fields in Isabela and Cagayan provinces.
Agriculture officials said the rice farms were about one to two weeks from harvest but were threatened by rain-swollen rivers.
Disaster officials said they were monitoring the progress of Hagibis, which means "rapidity" in the Philippines' Tagalog language, but no new evacuations have been ordered.
The Philippine weather bureau said it was also monitoring another weather system in the Pacific Ocean that might hit the country later this week.
Storms regularly batter the Philippines and this year the central government in Manila ordered pre-emptive evacuations to try to avoid a repeat of last year's devastating Typhoon Durian, which killed 1,200 and left 120,000 homeless when it crashed through Bicol in December.
