Four Pakistani soldiers were killed in a terrorist attack from Afghanistan while they were working on fencing the Pakistan-Afghan border in the restive Balochistan province on Wednesday, the Army said.

A team of paramilitary Frontier Corps (FC) was targeted in Manzakai Sector located in the Zhob district of Balochistan province in the south-west of the country, the Inter-Services Public Relations (ISPR) of the military said in a statement.

Four soldiers were killed and six others were injured in the incident, it said.

''Terrorists from across Afghanistan ambushed FC troops moving for fencing... FC troops responded promptly,'' the statement said.

It did not confirm whether there were casualties on the Afghan side.

The injured have been sent to a military hospital in Quetta for treatment.

Reacting to the incident, Interior Minister Sheikh Rashid Ahmad said that fencing would be completed at every cost.

Pakistan shares more than 2,600 km long border with Afghanistan which it began fencing in 2017 to stop incursion by the militants as well illegal border crossing by ordinary people and criminals. Officials have said that more than 85 per cent of fencing has been completed.

However, Afghanistan does not recognise the border, known as the Durand line, which separates the ethnic Pashtuns on both sides of the border. In the past, the fencing teams have come under attacks from Afghan forces which opposed the move as well as by the militants who used the porous border to launch attacks.