ISLAMABAD: Days ahead of the start of a drawdown of US troops from Afghanistan, Islamabad and Kabul are locked in fresh acrimony and tension over cross-border raids by militants into Pakistan and firing of mortar rounds.

The friction is threatening to undermine the recent improvement in relations between the two countries achieved after years of hostility, something that was being billed as this year’s only positive story on the foreign relations front other than revival of peace talks with India, which too have lately run into problems.

President Hamid Karzai’s spokesman Waheed Omar, talking to Dawn from Kabul, accused the Pakistan government of not responding to his country’s concerns about incidents of shelling of Afghan border areas.

He said the matter had been raised by President Karzai with President Asif Zardari, Army chief Gen Ashfaq Parvez Kayani and Foreign Secretary Salman Bashir over the past few days, but “there has been no response on Pakistan’s part”.

Pakistan army had earlier this week said that the mortar rounds could have “accidentally crossed the border” and denied that the shelling was intentional.

However, the issue got complicated with the Afghan National Army (ANA) firing rounds into Pakistani territory.

The Karzai administration has come under increased pressure from the eastern Afghan provinces and several public protests have been held against the mortar firing incidents in Kabul, Jalalabad and other cities.

Omar said the shelling from Pakistan “has caused a lot of public anger”.

He said the Afghan government was seeking to convey the message to Islamabad through diplomatic channels and did not want to “destroy the trust”.

A journalist from Kabul seconded the spokesman’s view about the pressure, but said the Afghan president was likely to show a lot of restraint because of his compulsions.

Pakistani military commanders say the root of the problem lies in Afghanistan where militants have sanctuaries in areas bordering Pakistan from where they “launch attacks on our posts”.

There have been five major raids by militants based in eastern Afghanistan. The militants, many of whom had fled operations in Bajaur, Mohmand and Swat, are occupying an area between River Kunar and the border because of a void created by withdrawal of Isaf forces from the area.

“They attack the Pakistani areas to regain the territory lost because of army operations,” a military official said. Pakistan has protested over militant attacks with the Afghan government, Isaf and ANA.

Military officials say when Pakistani forces retaliate against the militant attacks some rounds possibly land in Afghan territory.

“We have told Isaf and the ANA about the presence of Swati Taliban and militants led by Faqir Mohammad (Bajaur) and Abdul Wali (Mohmand),” a military official said, adding no action was being taken against their sanctuaries.

Another official said there was no doubt that they had tacit support of regional leaders and some elements within the Afghan government.

“There could be no other explanation for groups of 200-300 militants moving in Kunar to launch attacks on Pakistani posts. They have a continuous supply line of arms and finances in addition to logistical support.”

He expressed fear that a ‘game’ was being played at the behest of some regional stakeholders who were averse to Pakistan-Afghan rapprochement.

During a recent operation against militants, the army seized a large quantity of Indian, American, Russian and Chinese weapons and ammunition.