At least four people were killed and 57 were injured in a powerful earthquake in Taiwan.
The four known victims died in Hualien County - the epicentre of the quake that struck around 8am on Wednesday.
Taiwan's earthquake monitoring agency measured it at a magnitude 7.2 on the Richter scale - the US Geological Survey put the earthquake at 7.4.
This would make it the strongest earthquake to hit Taiwan, which are common occurrences in the East Asian country, in a quarter century.
The quake also caused a small tsunami which hit southern Japanese islands. There has been no report of injury or damage from this, Japan's chief cabinet secretary Yoshimasa Hayashi said.
He urged the residents in the Okinawa region to stay on high ground until all tsunami advisories are lifted.
Mr Hayashi also cautioned the people against disinformation and urged them to stay calm and help each other.
The Japan Meteorological Agency had forecast a tsunami of up to three metres for the southern Japanese island group of Okinawa.
A five-storey building in Taiwan's Hualien appeared heavily damaged with the first floor collapsing and leaving the rest leaning at a 45-degree angle.
In the capital Taipei, tiles fell from older buildings and within some newer office complexes.
The earthquake struck at 7.58am with the epicentre about 11 miles south-southwest of Hualien and 22 miles deep.
Train services were suspended across the island of 23 million people, as was subway service in Taipei, where a newly constructed above-ground line partially separated.
The national legislature, a converted school built before the Second World War, also had damage to walls and ceilings.
Schools evacuated their students to sports fields, equipping them with yellow safety helmets.
Some also covered themselves with textbooks to guard against falling objects as aftershocks continued.
Traffic along the east coast was brought to a virtual standstill, with landslides and falling debris hitting tunnels and highways in the mountainous region.
Taipei resident Hsien-hsuen Keng said: "Earthquakes are a common occurrence, and I've grown accustomed to them. But today was the first time I was scared to tears by an earthquake. I was awakened by the earthquake. I had never felt such intense shaking before."
She said her fifth-floor apartment shook so hard that "apart from earthquake drills in elementary school, this was the first time I had experienced such a situation".
Wu Chien-fu, the head of Taiwan's earthquake monitoring bureau, said effects were detected as far away as Kinmen, a Taiwanese-controlled island off the coast of China.
Chinese media confirmed the earthquake was felt in Shanghai and several provinces along China's south-eastern coast.
China and Taiwan are about 100 miles apart. China issued no tsunami warnings for the Chinese mainland.
Residents of China's Fujian province reported violent shaking, according to online outlet Jimu News.
One man told Jimu that the shaking awakened him and lasted about a minute.
In the Philippines, residents along the northern coast were told to evacuate to higher ground, but no major tsunami was reported about three hours after the quake.
Villagers in the provinces of Batanes, Cagayan, Ilocos Norte and Isabela were asked not to return to their homes until the tsunami alert was lifted, Teresito Bacolcol from the Philippine Institute of Volcanology and Seismology said.
The Pacific Tsunami Warning Centre said there was no tsunami threat to Hawaii or Guam.
The quake was believed to be the biggest in Taiwan since one in 1999 caused extensive damage.
Taiwan lies along the Pacific 'Ring of Fire', the line of seismic faults encircling the Pacific Ocean where most of the world's earthquakes occur.
Taiwan's worst quake in recent years struck in 1999, with a magnitude of 7.7, causing 2,400 deaths, injuring around 100,000 and destroying thousands of buildings.
