A Pakistani victim of cross border firing rests at a hospital in Quetta. Afghan security forces backed by artillery fired on Pakistani census workers and soldiers escorting them near the Afghan border, killing many civilians and wounding others, Pakistani army and government officials. Picture: Arshad Butt/AP

Quetta, Pakistan - Clashes erupted between Pakistani and Afghan troops on Friday along their disputed border killing several people, officials said, in another blow to already tense relations between the neighbours.

Pakistan's foreign ministry summoned Afghanistan's charge d’affaires in Islamabad to protest, calling the firing "unprovoked" and saying several people died, without specifying numbers.

Pakistan's military said the clashes broke out in a remote village near the border town of Chaman as a Pakistani census team, guarded by troops from its Frontier Corps (FC), was collecting population figures. It said at least one person was killed.

"Afghan border police opens fire on FC detailed for security of population census team," said Pakistan military's media wing, adding that 18 people were wounded.

"Exchange of fire continues. Chaman crossing closed."

The Chaman crossing into Afghanistan's Kandahar province is one of two main crossing points on the border.

A doctor in a hospital in Chaman told Reuters that three people had been killed in the fighting.

Zia Durani, police spokesman for Afghanistan's Kandahar province, said Pakistani officials were using the census as a cover for "malicious activities and to provoke villagers against the government".

"They did not heed the warning and we have clear orders to engage them," Durani said, adding two Afghan border police were wounded.

Relations between the countries have been uneasy since Pakistan's independence in 1947. Afghanistan has traditionally enjoyed better ties with Pakistan's arch rival, India.

Afghanistan has for years accused Pakistan of sheltering Afghan Taliban militants on its soil. Pakistan officially denies that even though various Taliban leaders have over the years been killed, died and detained in Pakistan.

Tension has been increasing in recent months amid new exchanges of accusations of not doing enough to tackle militants engaging in cross-border raids.

Pakistan's military said Afghan border police had been "creating hurdles" since April 30 for the census team in the Chaman area.

"This was done despite the fact that Afghan authorities had been informed well in advance and coordination was carried out through diplomatic and military channels for conduct of the census," the military said.

Last year, Pakistan started building a barrier at the main border crossing in the town of Torkham, near the Khyber Pass, angering Afghanistan which rejects the colonial-era Durand Line border drawn up in 1893.

Afghanistan has never formally recognised the line as the border. 

Reuters