Pakistan and Afghanistan have traded allegations over a deadly border firing incident that caused casualties on both sides, it was reported on Saturday.

In a statement late Saturday, the Foreign Office here said that Pakistani troops had responded to firing by the Afghan forces, reports Dawn news.

"Pakistani Force did not open fire first and responded in self-defence only," it said while rejecting Afghan allegation of firing at the civilian population.

Information Minister Senator Shibli Faraz said certain people had tried to cross the Chaman border forcibly and at the same time gunshots were fired from the Afghan side.

The incident took place on Thursday after an unruly mob attacked the Frontier Corps offices and a quarantine centre at the Chaman border crossing following a protest over restrictions on pedestrian crossing because of the COVID-19 pandemic.

In the ensuing clash, four people were killed.

Afghan authorities had claimed that 15 people were killed in Spin Boldak due to the shelling.

Meanwhile, Afghan media reports said that forces acted while the unrest was happening on the Pakistani side.

"Pakistani forces reportedly opened fire on the protesters. In response to Pakistani security forces, the Afghan border forces came in action and exchanged fire with Pakistani forces," Dawn news quoted the Afghan Islamic Press as saying in a report.

According to a statement from the Afghan defence ministry, Chief of General Staff of the Afghan Armed Forces Gen Muhammad Yasin Zia ordered "befitting response" to Pakistani troops.

He directed provision of small and heavy weapons to the Afghan forces deployed along the border.

The Afghan National Security Council, meanwhile, in a statement said the matter would be pursued through relevant channels and "required action" will be taken.(IANS)