The US State Department has imposed sanctions on Syrian President Bashar Assad's eldest son, Hafez, keeping up pressure on the leader and his inner circle.<br />''<br />''Separately, the US Treasury Department announced it had imposed sanctions on prominent Syrian businessman Wassim al-Qattan and nine entities for enriching the Syrian regime through construction of luxury real estate.<br />''<br />''The Treasury sanctions are the result of legislation known as the Caesar Syria Civilian Protection Act, named after the pseudonym of a Syrian policeman who turned over photographs of thousands of victims of torture by the Assad Government.<br />''<br />''Sanctions imposed last month included Assad and his wife, Asmaa, members of the extended Assad family, senior military leaders and business executives.<br />''<br />''It was the first time that the sanctions name any of Bashar Assad's three children. <br />