A shadowy, Pakistan-based militant faction is on the rise within the Taliban after its leader was appointed deputy and played a key role in unifying the fractured insurgency. The ascendency of the Haqqani network could significantly strengthen the Taliban and herald another summer of fierce fighting in Afghanistan. The firepower it brings to the Taliban was shown by a Kabul bombing last month that killed 64 people, the deadliest in the Afghan capital in years, which experts say was too sophisticated for the insurgents to have carried out without the Haqqanis. The network's role could also further poison already tainted relations between Islamabad and Kabul. Afghanistan is pressing Pakistan to crack down on the Haqqanis, accusing it of tolerating the group, a charge the Pakistanis deny. An audio recording of a recent meeting of the top Taliban leadership offers a glimpse into the influence the Haqqani network now holds within the movement. Sirajuddin Haqqani, the network's leader and newly elevated deputy head of the Taliban, tells the gathering that they must end differences and focus on fighting. "It is time to work. The mujahedeen are happily going to the battlefield," he is heard saying. The voice is recognizable as Haqqani's. Haqqani's rise to the deputy post is the highest, most direct role that the network is known to have taken in the Taliban leadership. The network pledged allegiance to the Taliban years ago but has traditionally operated independently. The network was founded by Jalaluddin Haqqani, a one-time ally of the United States who achieved fame fighting the Soviets in Afghanistan in the 1980s and who developed close ties to the slain Al-Qaeda chief Osama Bin Laden. After his death, his son Sirajuddin Haqqani took over. — AP