Pakistan's top Taliban leader, Baitullah Mehsud, is buying children as young as 7 to serve as suicide bombers in the growing spate of attacks against Pakistani, Afghan and U.S. targets, U.S. Defense Department and Pakistani officials say.

A Pakistani official, who spoke on the condition that he not be named because of the sensitive nature of the topic, said the going price for child bombers was $7,000 to $14,000 - huge sums in Pakistan, where per-capita income is about $2,600 a year.

"[Mehsud] produces these suicide bombers, which are sold or bartered, which can be used by [Afghan Taliban leader Mullah] Omar's Taliban or ... other groups," the U.S. official said.

In some cases, he said, the children are kidnapped and then sold to Mehsud.