The Obama administration extended its Libya sanctions to more Gadhafi family members and close advisers on Thursday, blacklisting business with the Libyan leader's wife, four of his children and his chief of military intelligence.

The Treasury Department froze the assets of nine Libyans in all as part of the strategy to peel off Moammar Gadhafi's closest advisers while punishing those who remain loyal to the regime even as it commits human rights violations.

The sanctions come on top of those previously announced by the administration, which accounted for $32 billion in Libyan government assets blocked in the United States.

The additions include Abdullah al-Senussi, a colonel who heads Libya's military intelligence, whom the U.S. blames for organizing mass killings in the eastern city of Benghazi and recruiting foreign mercenaries to fight for Gadhafi's regime. Al-Senussi is allegedly responsible for the deaths of 1,200 Islamists in Abu Selim prison in 1996, Treasury's statement said.

Defense Minister Abu Bakr Yunis Jabir, external security director Abu Zaid Dorda and public works chief Matuq Mohammad Matuq also were targeted.

From Gadhafi's family, the list now includes Gadhafi's wife, Safia Farkash, and four of his children: Hannibal Gadhafi, head of the General Maritime Transport Company of Libya; Saadi Gadhafi, special forces commander and Libya's soccer federation chief; Muhammad Gadhafi, Libya's Olympic chief and chairman of the General Post and Telecommunications Company; and Saif al-Arab Gadhafi.

"Today's designation should send a strong signal to those responsible for the violence inflicted by Gadhafi and his government that the United States will continue steps to increase pressure and to hold them accountable," said David S. Cohen, acting head of Treasury's sanctions department.