Kabul, Afghanistan - An obscure Pakistani extremist cell has claimed responsibility for the unprecedented bombing of a Shiite religious ceremony in Kabul, but there are growing fears across Afghanistan the attack could open a new, sectarian front in the country's long-running war.
The little-known, but radical, Lashkar-e-Jhangvi al-Alami, based in Pakistan's tribal areas, yesterday claimed it was behind the suicide bombing at the Abul Fazl shrine in Kabul's old city, which killed 58 people and injured more than 100.
A spokesman who rang a Pashto radio station yesterday also claimed responsibility for a second bombing in the northern city of Mazar-i-Sharif, which killed four people.
Afghan President Hamid Karzai cancelled his planned visit to Britain in the wake of the bombings and headed back to Kabul.
Both attacks were near mosques where Shiites were commemorating Ashura, a holy day that marks the death of the grandson of the prophet Muhammad.
Lashkar-e-Jhangvi al-Alami, or ''Global Lashkar-e-Jhangvi'', is an offshoot of Lashkar-e-Jhangvi, a group that has systematically assassinated Shiites and attacked their religious gatherings for years in Pakistan. The group has been linked with al-Qaeda, but also with the Pakistani government's notorious intelligence agency, the ISI.
It is also believed to have been behind the 2008 bombing of the Marriott hotel in Islamabad, as well as the armed attack on the Sri Lankan cricket team in Lahore in 2009. But this attack would mark the group's first foray into Afghanistan.
There are concerns these bombings could begin a new wave of internecine attacks between Sunni Muslims, who make up about 80 per cent of Afghanistan's population, and Shiites, who make up about 19 per cent.
Sunni and Shiite students clashed in Mazar-i-Sharif yesterday. Most Shiites are ethnic Hazaras, and faced brutal oppression under the Taliban. The majority of the Afghan refugees who have come to Australia are ethnic Hazaras.
Afghan Shiite leader and MP Mohammad Mohaqiq said those behind the attack ''want to trigger a sectarian war''. He appealed for calm among aggrieved Shiites, but warned ''we will not forget this attack''. ''We will have our revenge on our enemies.''
He blamed Afghanistan's troubled neighbour for the bombings.
''It is obvious it is Pakistan. Pakistan is always trying to carry out violent attacks in Afghanistan.''
Kate Clark, from the Afghanistan Analysts Network, said there was hope sectarian tensions could be restrained.
''Promoting sectarianism in Afghanistan is playing with fire. But, so far, all sides have condemned the attack and seem intent on trying to contain the fallout.''
And the fact the Taliban has condemned the attacks ''is some relief''.
''If the attacks had been ordered by the Taliban leadership, it would have marked a dangerous development in the insurgency''.