President Bush on Wednesday authorized freezing the assets of anyone involved in the 2005 assassination of former Lebanese prime minister Rafik Hariri.

Bush underscored suspicions about Syrian involvement in the Beirut truck bombing that killed Hariri and 20 others. A U.N. investigative commission has linked Syrian and Lebanese intelligence agents to Hariri's death. Syrian President Bashar Assad has denied the charges.

In an executive order, Bush authorized the secretary of the Treasury to freeze assets of people yet-to-be-identified who are determined to have been involved in Hariri's death or to have obstructed the work of the U.N. investigators. The order designates criteria for the Treasury to use in making its judgments.

National Security Council spokesman Frederick Jones said the order was tangible evidence of Bush's commitment to see that justice is done. "It is another tool in the implementation of action against those who were complicit in the assassination of Prime Minister Hariri," he said.

The order builds on an executive order that Bush issued in 2004 declaring a national emergency concerning Syria in the aftermath of Hariri's assassination.