Islamabad, Pakistan (CNN) -- A suspected al Qaeda member believed to have played a key role in a deadly December attack on CIA employees in Afghanistan appears to have been killed, a U.S. counterterrorism official told CNN Wednesday.
Hussein al-Yemeni was the apparent victim of a strike last week in the Miran Shah area of Pakistan, said the official, who called al-Yemeni "a vicious and dangerous figure who saw himself as an up-and-comer in the terrorist world."
CNN was unable to reach officials in Pakistan Wednesday to confirm the death.
Al-Yemeni was believed to be in his late 20s or early 30s and had apparent ties to insurgent groups in Yemen, Afghanistan and Pakistan, the official said.
Al-Yemeni is thought to have played a key role in the December 30 suicide attack on a U.S. base in southeastern Afghanistan's Khost province, the official said. Seven CIA employees and contractors were killed in the attack, the greatest loss of life for the agency since the 1983 bombing of the U.S. Embassy in Beirut, Lebanon, which killed eight agents.
The official did not specify who was responsible for the strike or how it was carried out.
The Pakistani and U.S. militaries have been working to rout suspected militants from within the country's borders in the form of airstrikes and arrests. Earlier Wednesday, back-to-back drone strikes killed five suspected militants in the country's northwest tribal region, and at least six Taliban leaders have been arrested in the past month, according to Pakistani officials.
"Al-Yemeni would be the latest victory in a systematic campaign that has pounded al Qaeda and its allies, depriving them of leaders, plotters, and fighters," the U.S. official said. "For them, there can be neither safety nor rest."
CNN's Pam Benson contributed to this report.