KABUL — The Afghan Taliban issued a written statement on Sunday purportedly quoting Jalaluddin Haqqani, the leader of the Haqqani insurgent group, in an effort to quell rumors of his death. The statement, posted to the Taliban's website, quoted Haqqani mourning the loss of Mullah Mohammad Omar, the leader of the group whose death the extremists confirmed last week. The Afghan government says Mullah Omar died in April 2013. The Taliban have announced that Mullah Akhtar Mohammad Mansoor is their new leader and released a purported audio statement from him on Saturday. The statement released on Sunday did not include any audio of Haqqani speaking to prove he is alive, however it comes as the Taliban tries to present a unified front behind Mansoor as they continue their nearly 14-year insurgency against the Afghan government. Relatives of Mullah Omar, including his son Yacoob, have said they do not support Mansoor, hinting at fissures between those who want to continue fledgling peace talks and the movement's more extreme elements. The statement on Sunday said Haqqani backed Mansoor as the Taliban's leader. “My particular recommendation to all members of the Islamic Emirate is to maintain their internal unity and discipline,” the statement quotes Haqqani as saying, using the Taliban's name for Afghanistan. The statement added Haqqani said followers should not be deceived by enemy propaganda. Haqqani is the leader of the Haqqani Network, a terrorist group based in Pakistan's lawless tribal areas that is believed to have conducted many bloody attacks inside Afghanistan. While it rarely claims responsibility for its attacks, they are usually identifiable by their use of complex tactics, like a large number of assailants including suicide bombers. Rumors of Haqqani's death have circulated and been denied by militants for the past year. If Mansoor fails to appease Taliban fighters and field commanders on the ground, the ultimate beneficiary could be Daesh. The rival extremist group, which already controls about a third of Syria and Iraq with affiliates in Egypt and Libya, has established a small foothold in Afghanistan and is actively recruiting disillusioned Taliban fighters. Meanwhile, as Taliban representatives have attended peace talks with Afghan government officials, the extremists have intensified their attacks on local security forces after NATO and U.S. troops ended their combat mission at the end of last year. — AP