Santiago de Cuba, January 18 (RHC)-- Residents of eastern Santiago de Cuba are on alert following a number of moderate earthquakes early Sunday morning. Reports from the area say that security measures are being implemented by Civil Defense authorities.

The first tremor – measuring 4.8 on the Richter scale -- was felt in Santiago de Cuba at 1:37 Sunday morning, which was followed by a series of other seismic events during the next 12 hours.

No human or material damage was reported. However, authorities insisted that people remain on alert. Monitoring stations reported a continued seismic activity, but at lower levels.

Experts say that 70 percent of high magnitude quakes are preceded by a series of minor tremors. In many cases, a series of tremors increases seismic activity, which later goes back to normal, but attention must be closely paid.