It comes just days after three similar tremors
Two people have died and dozens of others are trapped in buildings after a series of earthquakes shook a city on the east coast of Taiwan.
The United States Geological Survey (USGS) says they measured 4.8, 4.6, 6.4 and 5.1 respectively.
They were all east of the city of Hualian.
The country's official Central News Agency says the ground floor of the Marshal Hotel has caved in and people are believed to be trapped inside.
"Two people were unfortunately killed, and 114 have suffered light or severe injuries," Taiwan's premier William Lai told an emergency government meeting.
Local media reported the two people killed were hotel employees.
Four other buildings, including two hotels, also tilted during the earthquakes and the government also confirmed that a military hospital had been damaged during the earthquake.
The tremor was felt shortly before midnight on Tuesday, forcing the closure of a busy road nearby.
The government said a bridge in the city on Taiwan's eastern coast could not be used, and the structure of an inn had tilted during the earthquake.
The president's office said in a statement following the second earthquake: "The president (Tsai Ing-wen) has asked the cabinet and related ministries to immediately launch the disaster mechanism and to work at the fastest rate on disaster relief work."
It comes just days after thee similar tremors hit the same region.
The Department of Foreign Affairs says it is aware of the earthquake affecting Taiwan.
It says Irish citizens should follow the advice of the local authorities.
Those requiring advice or assistance can contact the department at 00-353-1-408-2527 or 00-353-1-408-2000.
We are aware of the earthquake affecting Taiwan. Citizens should follow the advice of the local authorities. If any advice or assistance is required, citizens or their family can contact us at 01 408 2527 or 01 408 2000.— DFATravelWise (@dfatravelwise) February 6, 2018
Taiwan lies near the junction of two tectonic plates and is regularly hit by earthquakes.
The island's worst tremor in recent decades was a 7.6 magnitude quake in September 1999 which killed around 2,400 people.
Additional reporting: IRN