A strong earthquake struck off Taiwan on Thursday, causing buildings to shake violently in Taipei but with no immediate reports of damage or injury.

The quake was of magnitude 6.2, the US Geological Survey which monitors earthquakes worldwide, initially said. It later downgraded this to 6.1.

The quake struck off Yilan City on the island's east coast at a depth of 73 kilometres (45 miles) at 9:19 pm local time (1319 GMT), according to the USGS.

Taipei residents reported shaking buildings, with the quake felt across the island.

"My building shook violently and I took my son and fled our home. It's deathly terrifying," wrote one social media user in Taipei.

Chen Kuo-chang, head of the Central Weather Bureau's Seismological Center, said the earthquake was the strongest this year.

"The earthquake was felt all over Taiwan," he said, with tremors lasting for around 30 to 40 seconds.

Recent heavy rainfall around the cities of Yilan and New Taipei meant that authorities should be on guard for mudslides in the surrounding mountains, Chen added.

Vice President William Lai urged calm, posting on Facebook that the government was monitoring the situation.

There have been no immediate reports of serious damage or injuries.

But residents in Taipei said they were jolted by the quake, with an AFP reporter saying that she felt her building sway and heard sirens in the distance as she scrambled across her apartment.

Taiwan is regularly hit by earthquakes as the island lies near the junction of two tectonic plates
Taiwan is regularly hit by earthquakes as the island lies near the junction of two tectonic plates AFP / Sam YEH

"It's shaking so powerfully for so long in New Taipei City," said one Facebook user.

"I thought my house was going to collapse and I was wrecked. Thankfully there's no damage," she added.

Taiwanese TV showed videos of goods falling from the shelves, and clips of roof tiles coming off buildings.

"HUGE earthquake just now in Taiwan," wrote a Twitter user who said he was driving home from work when the quake struck.

"Thought I'd blown a flat tyre... turned out to be a big quake!"

Authorities said service on Taipei's metro was temporarily suspended while they carried out impact assessments.

Some high-speed train services were also delayed because of the quake, according to the rail operator's website.

Taiwan is regularly hit by earthquakes as the island lies near the junction of two tectonic plates.

Hualien, a scenic tourist hotspot, was struck by a 6.4-magnitude earthquake in 2018 that killed 17 people and injured nearly 300.

In September 1999, a 7.6-magnitude quake killed around 2,400 people in the deadliest natural disaster in the island's history.