PESHAWAR: At least four soldiers were killed and four others injured Wednesday when militants from the Afghan side of the border attacked a military post in Bajaur tribal region, military officials said.

The military’s media wing, the Inter-Services Public Relations (ISPR), confirmed that the attack took place on Manozangal and Moukha top checkposts and was repulsed by security forces.

“In Bajaur region during the early morning today, terrorists from across the border fired on Pakistani border posts,” said a military source. “Four soldiers were martyred and four are injured.

Sources said this was the third cross-border attack by militants since May 25.

“This is the third incident of cross-border attacks and firing since May 25 from Afghanistan,” said one source.

Moreover, intelligence sources suspect that Tehrik-i-Taliban Pakistan (TTP) chief Mullah Fazlullah-led militants based in Kunar and Nuristan along with factions based in Bajaur and Mohmand tribal areas may be involved in the cross-border attacks along with what they described as foreign elements.

Soon after the attack, the Pakistani foreign office condemned the attack and said it had raised the issue with the Afghan government in Kabul and with the country's embassy in Islamabad.

“This matter has been raised with the Afghan government in Kabul and with their Embassy in Islamabad,” said a statement from the foreign office. “Afghanistan must take concrete steps to stop the use of its territory against Pakistan.”

Bajaur agency sits directly across Afghanistan’s Kunar province where a large number of suspected militants who had fled operations in Swat and Bajaur have been living for the last few years. These people have in the past launched similar cross-border attacks.

Reuters adds: Pakistan launched its first major ground offensive in years against insurgents near the Afghan border on May 22 after several rounds of government-led peace talks ended in failure.

Afghanistan claims hundreds of rockets and bombs have landed in Afghan villages close to the border since the offensive began 11 days ago.

Last month, Pakistan lodged a formal complaint with Afghanistan after a military post in Bajaur came under heavy attack from suspected Taliban fighters, killing one soldier.

The attacks on Wednesday come days after the Pakistani Taliban split into two groups, limiting the government's chances of finding a negotiated settlement to end the insurgency.

The breakaway group is said to be in favour of peace talks with the government while the main insurgency has announced that it will continue attacks against government and security targets.