A spokesman for a top Taliban leader in Pakistan denied Saturday a US media report that al-Qaida's No. 2 leader, Ayman al-Zawahri, may have been critically wounded or killed in a missile strike in recent days. CBS News reported Friday it had obtained a copy of an intercepted letter from unidentified sources in Pakistan which urgently requested a doctor to treat al-Zawahri. The letter was purportedly from Taliban leader Baitullah Mehsud and said al-Zawahri was in "severe pain" and his "injuries are infected." Mehsud spokesman Maulvi Umar said, "We deny it categorically." Pakistan army and intelligence officials also said they had no information that al-Zawahri was hit in a missile strike reported Monday in South Waziristan. US officials have yet to confirm it was a US missile strike. Pakistani intelligence say they think al-Qaida explosives expert Abu Khabab al-Misri was among six people killed in the attack. Umar, who spoke by telephone from an undisclosed location inside Pakistan, claimed only religious students died in the attack. "Whenever America targets and kills innocent people it comes up with such propaganda, that it has killed a big personality, in an attempt to justify the cruelty it has done," he said. According to the CBS report, the intercepted letter was signed by Baitullah Mehsud, a local Taliban leader, whose seal on the letter was said by experts to be legitimate. It is dated July 29 - a day after al-Qaida weapons expert Abu Khabab al-Masri was reportedly killed in a US missile strike. While American authorities said they did not know if al-Zawahiri was present during the attack, US officials told CBS that they were investigating reports that he had been killed.