Published: Feb 17, 2011 5:21 PM EST
Updated: Feb 17, 2011 2:21 PM EST

WASHINGTON (AP) - The Obama administration is expressing alarm over a violent crackdown on anti-government protesters in key U.S. ally Bahrain and urging authorities there to use restraint.

The State Department said Secretary of State Hillary Rodham Clinton called Bahrain's foreign minister on Thursday to register Washington's "deep concern" about overnight developments. Army patrols and tanks locked down the capital of the tiny Gulf kingdom after riot police fired tear gas and beat demonstrators demanding political reforms. At least four people were killed and the official said Clinton spoke with the foreign minister about how to respond to the protesters' demands.

The administration is watching the unrest in Bahrain with anxiety as the country is home to the U.S. Navy's 5th Fleet and a Middle East anchor of American defense strategy.

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