NATO on Monday said an investigation had found "no evidence of civilians injured or killed" in southern Afghanistan, where President Hamid Karzai said 52 villagers were killed by a rocket.

"Any speculation at this point of an alleged civilian casualty in Rigi Village is completely unfounded," ISAF Communication Director Rear Admiral Greg Smith was quoted saying in a statement.

"We are conducting a thorough joint investigation with our Afghan partners and will report any and all findings when known."

ISAF is NATO's International Security Assistance Force.

Karzai said Monday that NATO troops on Friday had fired a rocket that killed the "innocent" villagers.