ISLAMABAD, May 7 (Xinhua) -- A senior Pakistani military officer said Sunday that the country's security forces had killed over 50 Afghan security personnel in the recent cross-border firing.

Chief of the Pakistani paramilitary troops Major General Nadeem Ahmed said that about five Afghan posts were destroyed and more than 50 Afghan security personnel were killed in a recent exchange of firing and shelling.

Border troops of the two countries involved in hours of exchange of firing on Friday that caused casualties on both sides.

Pakistani army spokesman had said that the Afghan Border Police "opened fire" on Pakistani border forces Frontier Corps (FC) in charge of security of a population census team in southwestern Balochistan Province Friday.

However, Afghan officials had blamed Pakistan for "incursion" into Afghan side of the border.

Ahmed, however, described the events as unfortunate.

Afghan officials had confirmed the death of seven security personnel and some several civilians. Pakistan officials had said that three security men were among 12 people killed in the Afghan firing.

Both sides later declared ceasefire along the Chaman border.