According to the Vietnam Earthquake Information and Tsunami Warning Centre, the first earthquake, with a magnitude of 3.1, occurred at 4.08am.
It was followed by a second earthquake with a magnitude of 3.0 at 4.10am, a third with a magnitude of 2.6 at 4.46am, and a fourth with a magnitude of 2.9 at 9.28am.
The centre stated that the level of disaster risk is 0. The Vietnam Earthquake Information and Tsunami Warning Centre, part of the Institute of Earth Sciences, will continue monitoring the situation, it added.