Security is tightened in Pakistan as Taliban fighters secretly bury their leader Saturday.

Hakimullah Mehsud was reportedly killed in a U.S. drone strike Friday.

Pakistan's Interior Minister Chaudhry Nisar Ali Khan is now lashing out at the United States saying the attack was a U.S. bid to derail planned peace talks with the Taliban.

SOUNDBITE: Pakistani Interior Minister, Chaudhry Nisar Ali Khan saying:

"First and foremost, the government of Pakistan does not see this drone attack as an attack on an individual, but as an attack on the peace process."

He said Pakistan will review its relationship with the United States.

These sentiments were echoed by cricket legend-turned politician Imran Khan who wants to block NATO supply routes into Afghanistan.

The supply lines are crucial as NATO prepares to withdraw from Afghanistan by the end of next year.

The Taliban have killed thousands of Pakistani civilians and numerous members of the security forces.