A 5.4-magnitude aftershock struck Searles Valley, California – the epicenter of Thursday’s powerful earthquake.

The tremor was reported on Friday at about 4.07am local time, according to the US Geological Survey (USGS).

The first earthquake, a magnitude-6.4, occurred on the morning of Independence Day and was felt from Las Vegas to San Diego, reported NBC Los Angeles.

Several aftershocks – as many as 220 – followed within five hours of the original quake, but this is the strongest one yet.