Saudi Arabia on Wednesday denounced an alleged assassination plot against its ambassador to Washington as "outrageous and heinous" but said it was still trying to determine who was behind it.

The statement, issued after it was reviewed by King Abdullah, did not name Iran nor did it focus on the involvement of an officer of Iran's Quds force, the special operations unit of the Revolutionary Guard Corps that U.S. Attorney General Eric Holder linked to the alleged plot on Tuesday.

But an adviser to the Saudi government said that Gholam Shakuri, named in the U.S. Justice Department's criminal complaint as the Iranian official supporting the plot, was already known to the Saudi government as one of the officers who directed Iranian support to Shiite Muslims in Bahrain when they rose up in February to demand political rights from the minority Sunni regime.