Baja California, Mexico - A 5.1 magnitude earthquake shook northwestern Mexico and the nearby US early Tuesday morning. There were no immediate reports of injury or damage.

The epicenter of the temblor was in the state of Baja California, Mexico, within 11 miles of Guadalupe Victoria, Mexico, and within about 35 miles of San Luis, Arizona, the US Geological Service (USGS) reported. The focal depth of the shock was a relatively shallow 19 miles, according to the USGS.

The estimated "perceived shaking" near the quake epicenter was magnitude VI, or "strong," on the Mercali scale. Such shaking would have light to moderate damage potential, depending upon the vulnerability of affected buildings, the USGS website shows.

The tremor should have been felt weakly in the southern Imperial Valley near El Centro, California, and in southwestern Arizona near San Luis and Yuma.

The earthquake struck along the southern reaches of the San Andreas Fault system, which stretches from the Gulf of California to the seafloor off northern California.