Al-Qaeda has said it was responsible for last month's deadly suicide bombing at a U.S. base in southeast Afghanistan.

The December 30 attack at the Khost province base killed seven CIA employees and contractors and a Jordanian military officer.

In a statement posted on Islamist websites, Mustafa Abu Yazid, al-Qaeda's commander of operations in Afghanistan and number 3 in the group's hierarchy, said the attack was revenge for the death of Baitullah Mehsud, the leader of the Taliban in Pakistan, and senior al-Qaeda members Saleh al-Somali and Abdullah al-Libi.

All three were killed in CIA drone attacks on the volatile Pakistani-Afghan border.

The suicide bomber was identified as Humam Khalil Mohammed Abu Malal, a Jordanian doctor that U.S. intelligence officials have said was a double agent.

"May God accept him as a martyr who was able to infiltrate the Americans' forts," the statement said.

"We ask God to bless the people who follow your way," it went on. "Let them know that your brothers are following your path and they will not have peace of mind until they slaughter the Americans."

Several other militant groups have also claimed responsibility for the attack, one of the deadliest ever against the U.S. intelligence community.

MOSCOW, January 7 (RIA Novosti)