The typhoon passed near the island of Sabtang in the Batanes group late in the morning with maximum sustained winds of 170 kilometres (106 miles) an hour and gusts of up to 215 kilometres (134 miles) an hour.

Krathon was expected to head towards Taiwan, where authorities closed schools and evacuated more than 800 people in the south and east as a precaution.

The Philippines' weather service said in its latest bulletin that "significant to severe impacts from typhoon-force winds are possible" in Batanes, a province of some 20,000 people.

Batanes governor Marilou Cayco, reached by satellite phone by the DZBB radio station in Manila, said the typhoon began to hit the islands last night and that 27 families had been evacuated.

"The wind is so strong, it is like an earthquake," she said.

Cayco said "many" houses were damaged, with roofing sheets flying through the air.

"People are asking for help but we cannot go out" because it was too dangerous, she said.

There were no reports of casualties before electricity and telephone contact were cut by the strong winds, said a senior Batanes police official, who was on the main island of Luzon further south and asked not to be identified.

The police official also told AFP "pre-emptive evacuations" were undertaken shortly before the typhoon struck.

Police and rescue officials in Batanes province could not be reached by normal phone service.

Photos and video clips posted on social media showed coconut trees swaying violently in a white blanket of rain and fog on Batan and Sabtang, two of the islands that make up Batanes province.

- 'Be vigilant' -

In Taiwan, rain had started to batter Taipei as well as the eastern side of the island on Monday afternoon, although Krathon was not expected to make landfall until Wednesday.

Fishermen in the northern port city of Keelung tied down their boats, while authorities said schools and offices from southern Pingtung to eastern Hualien were already closed.

"People in the east half (of the island), northern mountainous areas, and southern areas should pay special attention," President Lai Ching-te said in a Facebook post, adding that the weather patterns of Krathon "are complex".

Krathon is currently categorised as a medium-strength typhoon but there is potential for its "intensity to increase when it passes the South China Sea", said Lu Kuo-chen, Taiwan's Central Weather Administration's deputy chief.

Premier Cho Jung-tai said: "We must not take it lightly and we must be vigilant."

"The typhoon is expected to bring strong winds and heavy rain, posing a great threat to all of Taiwan," Cho said.

Typhoons are common around the region at this time of year.

However, a recent study showed that they are increasingly forming closer to coastlines, intensifying more rapidly and lasting longer over land due to climate change.

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