General Aminullah Amerkhail, commander of the border police in the province of Nangarhar, said the shells -- what he said were the latest in a series of attacks -- “were fired by Pakistan security forces” stationed on the border.

“Nine artillery shells were fired near our posts in Goshta district,” he told AFP. “These were fired by Pakistani security forces. One of our police was injured.”But Pakistan's chief military spokesman, Major General Athar Abbas, told AFP by telephone in Islamabad: “We do not have any information in this regard.”Amerkhail said the attack was part of a wave of cross-border artillery strikes on Afghan soil from Pakistan in the same area over the past 10 days.

He added that 500 families had moved out of their homes and sought alternative shelter nearby as a result, but did not give details of any damage to buildings.

Last month, Afghan and Pakistani troops exchanged fire over the border, leaving one Pakistani soldier dead in the most serious clashes of their kind since 2007.

The disputed, unmarked border area between Afghanistan and Pakistan has been described by United States President Barack Obama as the most dangerous place in the world -- it is seen as the global headquarters of Al-Qaeda and the Taliban.

Afghanistan and Pakistan routinely trade accusations over border security, with each saying the other allows militants to infiltrate the porous and mountainous border, which is around 2,400 kilometres long, to carry out attacks. – AFP