This week's suicide bomb attack that killed dozens of Shi'ite Muslims at a Kabul shrine has significantly heightened tensions between Afghanistan and neighboring Pakistan. The Afghan president has vowed to confront Pakistan's government over the issue. Islamabad, for its part, is seeking to soothe riled emotions.
Kabul kept the pressure on Pakistan Thursday, following an apparent claim of responsibility by a Pakistan-based group for Tuesday's suicide bombing in the Afghan capital, which killed at least 55 Shi'ite worshippers on their holiest day of the year.
A spokesman for Afghan President Hamid Karzai was quoted Thursday as saying it is up to Pakistan to take action and find out how the Sunni extremist group Lashkar-i-Jhangvi managed contact the media in order to claim responsibility for the attack.
In Islamabad, Pakistan Foreign Ministry Spokesman Abdul Basit offered his country's condolences to the families of those killed and wounded.
"We obviously condemn in the strongest possible terms the reprehensible crime which was committed," said Basit. "We would encourage Kabul to share evidence, if any, with us through official channels. Because Pakistan and the people of Pakistan are committed to fight against terrorism."
Karzai's office, however, insists Pakistan needs to start taking action without waiting for evidence from Afghanistan.
The Kabul shrine attack was the deadliest of three bombings that took place in Afghanistan this week within a space of 48 hours.
The claim of responsibility by the outlawed Pakistani group Lashkar-e-Jhangvi adds to the growing list of irritants between Afghanistan and Pakistan. Kabul also suspects Pakistan was involved in an assault on the U.S. embassy in Kabul in September and in the assassination of chief Afghan peace negotiator Burhanuddin Rabbani just weeks later.
Pakistan boycotted this week's Bonn conference on Afghanistan's peace process to protest last month's deadly NATO airstrike that killed 24 Pakistani soldiers. Spokesman Basit dismissed suggestions the decision to boycott the conference constituted a retreat from peace efforts in Afghanistan.
"We would like to have a relationship that is free from recrimination and blame game... and we strongly believe in Islamabad that our two countries' destinies are intertwined," added Basit.
Experts fear this week's apparent targeted killing of Shi'ites may be the first salvo in a more sectarian dimension to the insurgency in Afghanistan, a development that would make the achievement of long-term stability far more challenging.