Updated

The Treasury Department is sanctioning three companies suspected of aiding the Syrian government, which is fighting opposition forces in a civil war that has killed more than 160,000 people.

The Treasury Department on Wednesday designated Pangates International Corp., a petroleum company based in the United Arab Emirates, for supplying materials to the Syrian government and the Syrian state oil company.

Also sanctioned were Expert Partners and Megatrade, two Syrian-based companies suspected of having links to Syria's weapons programs. The department says the two companies act on behalf of the U.S.-sanctioned Scientific Studies and Research Center. That's the Syrian agency responsible for developing and producing nonconventional weapons and ballistic missiles.

The action bans Americans from conducting transactions with the companies named and freezes any assets they may have under U.S. jurisdiction.