A 4.2-magnitude earthquake hit the northwestern province of Son La on Sunday, but no injuries or structural damages were reported.

The earthquake occurred in the Song Ma District and it was rather weak, according to the Center for Earthquake Information and Tsunami Forecasts under the Vietnam Institute of Geophysics.

It was the fifth earthquake that registered more than 3.5 on the Richter scale to hit the province since the middle of April.

Local scientists have warned that northwestern provinces should be prepared for more earthquakes in the future because the number of them in the region have proved the seismic fractures in Vietnam are becoming more active.