Published: Feb 02, 2011 10:49 PM EST
Updated: Feb 02, 2011 7:51 PM EST

WASHINGTON (AP) - Secretary of State Hillary Rodham Clinton has spoken with Egypt's new vice president to urge an investigation into violent attacks on protesters by pro-government supporters. She's apparently the first Cabinet-level official to reach out to Omar Suleiman, a longtime confidante of the U.S.

 State Department spokesman P.J. Crowley says Clinton condemned the violence and told Suleiman the government should hold to account those responsible.

Crowley says the U.S. does not know who unleashed what he called "thugs." He called the clashes a clear attempt to intimidate protesters.

Protesters claimed plainclothes police were among several thousand supporters of President Hosni Mubarak who attacked anti-government demonstrators in Cairo on Wednesday. Suleiman is an intelligence chief. He was appointed vice president last week in Mubarak's first major response to the unrest.

(Copyright 2011 by The Associated Press. All Rights Reserved.)