Earthquake tremors were felt by residents of Karachi's Gulshan-i-Iqbal and Gulistan-i-Jauhar areas on Tuesday.

Najeeb Amir, a deputy director at Met Department's Islamabad office, told DawnNews that a 3.6 magnitude earthquake struck the Gulshan-i-Iqbal area at a depth of 12 kilometres and its epicentre was Karachi.

The tremors were felt with most intensity in areas surrounding the University of Karachi campus, said the PMD official.

The quake of "moderate" intensity struck at 10:45am, another Met Office official told Dawn.com.

He said although quakes of this intensity do not cause destruction, after shocks could be expected to strike the area.

People took to social media to describe the scene, saying residents felt tremors and came out of their homes and offices located in the area.

Students attending classes at the University of Karachi and NED University came out of their classrooms.

Pakistan is located in the Indus-Tsangpo Suture Zone, which is roughly 200 km north of the Himalaya Front and is defined by an exposed ophiolite chain along its southern margin.

This region has the highest rates of seismicity and largest earthquakes in the Himalaya region, caused mainly by movement on thrust faults.

Along the western margin of the Tibetan Plateau, in the vicinity of south-eastern Afghanistan and western Pakistan, the South Asian plate translates obliquely relative to the Eurasia plate, resulting in a complex fold-and-thrust belt known as the Sulaiman Range.

Faulting in this region includes strike-slip, reverse-slip and oblique-slip motion and often results in shallow, destructive earthquakes.

The PMD recorded about 851 seismic disturbances in 2015.