Authorities on Thursday said that up to 40 militants were killed by security forces in clashes a day earlier in a remote tribal region near the Afghanistan border.
After a major operation on Wednesday in North Waziristan tribal district, the military had said at least 16 militants were killed and 19 captured.
An official statement by the tribal area administration in NWFP did not elaborate on the higher death toll.
"The clashes that took place between the miscreants and security forces in two different areas of North Waziristan Agency on Wednesday left as many as 40 miscreants dead," it said.
The army backed by gunship helicopters went into action in the Shawal region of North Waziristan after militants attacked a security post with rockets, killing three soldiers. Another soldier died in the ensuing clashes.