BEIJING - The 4.8-magnitude earthquake that hit North China's Tangshan Monday morning was an aftershock of the devastating quake that rocked the city in 1976, the China Earthquake Networks Center's (CENC) vice-director has said.

The city, in Hebei province, still sees aftershocks which belong to a normal range of movement in the earth's crust, and people do not need to panic, Zhang Xiaodong said during an interview on Monday.

"As time passes, the intensity of the aftershocks is decreasing," explained Zhang.

However, urbanization and the growing number of multi-storied buildings mean people have been able to detect the effects of relatively small quakes, Zhang added.

Tangshan experienced the latest tremor at 10:22 a.m. on Monday. Local people said minor tremors were also felt in Beijing and Tianjian, two megacities both within 200 kms of Tangshan.

The 7.8-magnitude Tangshan earthquake of 1976 left more than 240,000 people dead.