ISLAMABAD: Internet slowdown was experienced by users in various parts of Pakistan on Saturday, primarily due to overloading.

The country has already been facing low bandwidth due to the upgradation of the Web Management System, commonly referred to as an `internet firewall`, a senior executive of one of the cellular mobile operators said. He said the system is being upgraded to cater up to 9 terabytes internet traffic.

As PTI supporters neared Islamabad by Saturdaynoon, disruption in internet and social media services were reported from many parts of the country.

According to Netblocks, reports about disruption in WhatsApp services were received from Rawalpindi, Islamabad, Karachi and Lahore during the past 24 hours.

The suspension of cellular and mobile data services in the twin cities since Friday morning affected basic services like online banking, ride-hailing and food delivery services.

A senior official of the Pakistan Telecommunication Authority (PTA) said the Punjab government had also requested the suspension of cellular services in key cities of the province, but it was declined.

`[The] cellular services have been suspended in urban areas of Rawalpindi district and Islamabad due to serious concerns of threats by the security agencies,` the PTA official added.

He said the telecom regulator suspends cellular services at the request of security agencies. The PTA `is not authorised` to ask any security agency for details orthe nature of the security threat.

He said the request from the Punjab government was rejected as `there was no such threat in any city of Punjab`.