THE loss of scores of lives in bombings in Afghanistan on Tuesday and Wednesday has been tragic. Particularly alarming were Tuesday's attacks on Shia mourners observing Ashura in Kabul and Mazar-i-Sharif. The claim that sectarian violence is new to Afghanistan cannot be made so easily. Hazara Shias were targeted by the Taliban regime, including significant massacres in May 2000 and January 2001. While these incidents were also driven by ethnic tensions it is difficult to argue, given the Taliban's hard-line Sunni views, that they did not have a sectarian element. It is also true though that in recent years Afghan Shias have not been singled out in the same fashion. In this context a large-scale, clearly sectarian attack is a worrying development. Afghanistan is already torn along ideological, political and ethnic lines, and another divide is hardly needed at a time when security is being transitioned to Afghan forces. The Shia-Sunni conflagration that erupted in Iraq under the Americans is a reminder of how destabilising sectarian conflict can become in a country facing an ongoing war.

That said, restraint could have been exercised before immediately pointing fingers in Pakistan's direction. The only lead for this argument in the immediate aftermath was a phone call from an alleged operative of the Lashkar-i-Jhangvi, or an apparent offshoot, claiming responsibility for the Kabul attack. More evidence is needed before this connection can be made, and President Hamid Karzai would have done well to keep in mind previous knee-jerk accusations that have strained the relationship. For its part, Pakistan must take any evidence very seriously, as it might indicate a new ability and interest on the part of Pakistani militant groups in carrying out attacks in Afghanistan. If so this would mark an expansion of goals and a new level of cooperation with Afghan militants across the border, without which it is unlikely that attacks on this scale could have been carried out. If these incidents do indicate new militant aims and new patterns of collaboration across groups and across state lines, they serve as a wake-up call Pakistan cannot afford to ignore.