ISLAMABAD, May 7: Pakistan summoned the most senior Afghan diplomat in the country on Tuesday to protest over border skirmishes that it said left five security personnel wounded and strained bilateral relations.

Exchanges of fire and ensuing protests are threatening to worsen already fractious ties between Kabul and Islamabad, despite renewed efforts last month by US Secretary of State John Kerry to get them to work more closely on peace efforts.

Cross-border clashes flared up on Monday between Afghan and Pakistani security forces for the second time in five days with Kabul summoning the Pakistani charge d’ affaires in protest against the “unprovoked attack by Pakistani forces”.

The war of words over the porous frontier continued on Tuesday, with the foreign ministry in Islamabad summoning the Afghan charge d’affaires to warn against any repetition of what it too called “unprovoked firing”.

Five members of the paramilitary Frontier Constabulary were wounded in the firing on Monday morning, the ministry statement said.

Both countries have blamed each other for starting the firing on the border, which is a crucial battleground in the fight against Taliban militants who operate in both countries.

The border is unmarked in places and a key battleground in the fight against Taliban violence plaguing both countries.

“The Afghan charge d’ affaires was conveyed that in case of any further escalation as a result of this situation, the responsibility would be on the Afghan Government,” the statement said.

Meanwhile, hundreds rallied in a southern Afghan city on Tuesday in protest against the latest incidents along the Pak-Afghan border.

Hundreds of men marched through downtown Kandahar chanting “Death to Pakistan”.

The demonstrators, who dispersed peacefully after the march, were protesting two shooting incidents, one on Monday and one last week that resulted in the death of an Afghan border policeman and the wounding of several Pakistan troops.—Agencies