Pakistan's interior minister says he is unable to confirm reports that the leader of the Pakistani Taliban, Hakimullah Mehsud, was killed Thursday in a U.S. drone strike in the North Waziristan tribal region.

Rehman Malik told reporters in Islamabad Monday that unless he has “DNA evidence” or confirmation from his own “independent sources,” he will not say Mehsud is dead.

On Sunday, unnamed Pakistani intelligence officials said they had intercepted wireless radio conversations of the Taliban fighters discussing whether their chief was killed in the attack. Some of the overheard militants confirmed Mehsud was dead, while at least one criticized them for talking about it on the radio.

There was no official confirmation from Pakistan, and the Taliban issued a denial.