Army officials said as many as 100 soldiers were missing after the attack, although the exact number could not be confirmed.
The convoy was traveling between the towns of Wana and Ladha in the South Waziristan tribal region near Afghanistan.
Militants in the region this week released 15 Pakistani soldiers who had been abducted earlier this month.
Pakistan's tribal regions bordering Afghanistan have seen frequent terrorist attacks, and are believed to host militants loyal to Al-Qaeda and the Taliban.
(AFP, AP, Reuters)