The Pakistani Army said at least six Pakistanis were killed and 16 were injured when Afghan border troops resorted to “unprovoked and indiscriminate fire” across the border into Balochistan’s Chaman district.

Heavy weapons including artillery and mortars were used in the firing by Afghan personnel, according to the Inter-Services Public Relations (ISPR), the media wing of the military.

The incident has attracted condemnation across Pakistan, with Prime Minister Shehbaz Sharif issuing "strongest condemnation" over the deaths.

"Unprovoked shelling and fire by Afghan Border Forces at Chaman resulting in martyrdom of several Pakistani citizens and injuring more than a dozen is unfortunate and deserves the strongest condemnation. The Afghan interim government should ensure that such incidents are not repeated," said Sharif on Twitter.

Not the first incident lately

Last month, eight people, including two children and three paramilitary soldiers, were injured in Kurram district of Khyber-Pakhtunkhwa province when some Afghans from across the border opened fire at them over a dispute over the construction of a road.

The Chaman border crossing is also known as Friendship Gate connects Balochistan province to Afghanistan's Kandahar. It was closed last month after an armed Afghan crossed onto Pakistan's side of the border and opened fire on security troops, killing a soldier and injuring another two.

Pakistan has completed almost 90 per cent of fencing work along the border despite protests from Kabul, who contested the century-old British-era boundary demarcation that splits families on either side.

Successive regimes in Afghanistan, including the US-backed governments in the past have disputed the border and this has historically remained a contentious issue between the two neighbours. The border, known internationally as the Durand Line, named after the British civil servant, Mortimer Durrand, who had fixed the limits of British India after consultation with the then Afghan government in 1893.?

Pakistan-Taliban tensions

One of the reasons there have been wrinkles in Pakistan and Taliban's relations is over the Taliban's stance on militant group Tehreek-e-Taliban Pakistan (TTP). Pakistan had hoped that the Afghan Taliban after coming to power would use influence over the TTP to make peace with Pakistan but the expectation remained largely unfulfilled.

Earlier this month, Pakistan's head of mission in Kabul was also targeted in an assassination attempt.?

Outlook earlier reported that differences between the Pakistani government and Taliban regime in Afghanistan are growing.

Outlook's Seema Guha noted, "Initially Islamabad tried to downplay the differences and called for talks to sort out the irritants, but now Pakistan is also losing patience, more so because of the Tehreek-e-Taliban-Pakistan (TTP) ?or the Pakistani Taliban’s presence in Afghanistan. Using Afghanistan as a base they strike across the Durand Line on Pakistani territory. Despite repeated assurances, the Taliban has not acted against the TTP. They share the same ideology and is keen to convert Pakistan into a religious state with sharia law ?in place, much like in ?Afghanistan."

(With PTI inputs)