(Reuters) - A 7.2 magnitude earthquake rocked Taiwan on Wednesday, the strongest tremor to hit the island in at least 25 years, killing four people, injuring hundreds and sparking a tsunami warning for southern Japan and the Philippines that was later lifted.

Taiwan's government said four people had died in the mountainous, sparsely populated eastern county of Hualien near where the epicentre was, with 711 injured.

The fire department said 77 people remained trapped, some in collapsed buildings in Hualien.

Taiwan television stations showed footage of buildings at precarious angles in Hualien, where the quake struck just offshore around 8am (0000GMT) as people were going to work and school.

The quake was centered just off the east coast at a depth of 15.5km (9.6 miles), according to Taiwan's Central Weather Administration.

"It was very strong. It felt as if the house was going to topple," said 60-year-old Taipei hospital worker Chang Yu-lin.

The presidential office said president-elect Lai Ching-te, who takes office next month, would visit Hualien later on Wednesday.

Video showed rescuers using ladders to help people out of windows, while elsewhere, massive landslides caused by the tremors carved down hillsides.

There was also strong shaking felt on Taipei's subway system, which closed briefly to evacuate passengers though service resumed soon after on most lines.

Japan's weather agency, which put the earthquake's magnitude at 7.7, said several small tsunami waves reached parts of the southern prefecture of Okinawa.

The Philippines Seismology Agency issued a warning for residents in coastal areas of several provinces, urging them to evacuate to higher ground.

Taiwan also issued a tsunami warning, but reported no damage from that, and the Pacific Tsunami Warning Center in Hawaii later said the risk of damaging tsunami waves had passed.

Aftershocks could still be felt in Taipei, with more than 50 aftershocks registered, according to Taiwan's central weather administration.

Chinese state media said the quake was felt in China's Fujian province, while a Reuters witness said it was also felt in Shanghai.

Electricity operator Taipower said most power had been restored, adding that the island's two nuclear power stations were not affected by the temblor.

Taiwan's high speed rail operator said no damage or injuries were reported on its trains, but noted trains will be delayed while it carries out inspections.

Semiconductor giant Taiwan Semiconductor Manufacturing Co (2330.TW), opens new tab, a major Apple (AAPL.O), opens new tab and Nvidia (NVDA.O), opens new tab supplier, said it had evacuated some fabrication plants and its safety systems were operating normally.

"To ensure the safety of personnel, some fabs were evacuated according to company procedure. We are currently confirming the details of the impact," according to the company.

It later added that those evacuated were beginning to return to their workplaces.

Taiwan's benchmark share index (.TWII), opens new tab largely brushed off the impact of the earthquake, closing down 0.6%. TSMC's Taipei-listed shares ended down 1.3%.

Taiwan's official central news agency said the quake was the biggest to hit the island since 1999 when a 7.6 magnitude tremor killed around 2,400 people and destroyed or damaged 50,000 buildings in one of Taiwan's worst-recorded quakes.

Taiwan's Central Weather Administration said the earthquake registered the second-highest intensity of an "Upper 6" in Hualien county, on the 1-7 intensity scale.

In an Upper 6 earthquake, most unreinforced concrete-block walls collapse and people find it impossible to remain standing or move without crawling, the Japan Meteorological Agency says.