Taliban terrorists
Taliban terroristsReuters

The Taliban has admitted publicly for the first time that they covered up leader Mullah Mohammed Omar's death for over two years, in order to keep their ranks. 

On Monday, a new biography was posted in five languages online about the new Taliban chief, Mullah Akhtar Mansour, in an apparent attempt to unite discord within the terror group. 

In that text, the group admitted to covering up Omar's death since April 2013.

Afghan intelligence had previously stated in July that the Taliban cover-up had been in effect for 2-3 years, but could not confirm exactly when the archterrorist died.  

"Several key members of the supreme leading council of the Islamic Emirate (Taliban) and authentic religious scholars together decided on concealing the tragic news of passing away of (Omar)... and keep this secret limited to the very few colleagues who were already informed of this incorrigible loss," the biography stated, according to an AFP translation. 

"One of the main reasons behind this decision was... that 2013 was considered the final year of power testing between the mujahideen and foreign invaders who... had announced that at the end of 2014, all military operations by foreign troops would be concluded," they said, apparently referring to the North Atlantic Treaty Organization (NATO). NATO pulled out the majority of its troops from Afghanistan in December 2014. 

Omar led the Taliban to defeat rival Afghan militias in the civil war after Soviet troops withdrew in 1989. His alliance with Al-Qaeda leader Osama Bin Laden prompted the US to attack Afghanistan in 2001, and he has since been believed to be in hiding with a $10 million bounty on his head by the US.

The most recent statement purportedly from Omar in mid-July backed the ongoing peace talks between Taliban and the Afghan government, but it was published as text on a Taliban website instead of as a recording, strengthening suspicions that Omar was no longer alive.