A magnitude 4.5 earthquake occurred in waters off eastern Taiwan with a maximum intensity of level 4, weather authorities said late on Sept. 11. Shaking was felt in seven counties and cities.

The seas off eastern Taiwan lie along the boundary of the Philippine Sea and Eurasian plates, where quakes of magnitude 4 to 5 are relatively frequent. When the epicenter is offshore and at some depth, onshore damage often does not follow.

No immediate damage was reported in this case. Intensity 4 nonetheless describes shaking that moves indoor objects and swings hanging lights noticeably, enough for residents to feel clearly.

Taiwan operates an earthquake early warning system that sends alerts to mobile phones. Areas at some distance from the epicenter gain several to more than ten seconds before the shaking arrives.

Authorities are continuing observation in case of aftershocks. Tsunami risk is low for offshore quakes of modest magnitude, though separate notices are issued if alert thresholds are met.

Visitors to Taiwan are advised to check evacuation guidance at their accommodation as a basic precaution. The rule is to move only after shaking stops, watching for falling objects near stairwells and exits.