Tens of thousands of protesters in Bahrain are marching on a royal palace hours after clashes with police injured dozens of activists.
Security forces reinforced by pro-government Sunni vigilantes fired rubber bullets and tear gas late Friday to scatter protesters near the palace in the capital, Manama.
The latest unrest comes the same day as a visit by U.S. Defense Secretary Robert Gates, who was on a mission to encourage dialogue between the mostly Shiite protesters and the Sunni monarchy.
Gates told reporters on his flight home from the Mideast on Saturday that Bahrain and other Arab governments facing popular uprisings need to move quickly toward democratic reforms or risk giving Iran a chance to exploit the instability. He said the U.S. has no evidence Iran is behind any of the revolts.
Gates says he told Bahraini leaders Saturday that he believes the longer the protests drag on, the more opportunity Iran will see to exploit the divisions. Iran, a Shiite power in the region, is seen by Sunni-led countries such as Bahrain and Saudi Arabia as a serious threat.
Bahrain's monthlong uprising has deepened the sectarian divide between Sunni Muslims backing Bahrain's ruling dynasty and the Shiite protesters demanding it give up its monopoly on power.
Bahrain is a close U.S. ally and the home of the U.S. Navy's 5th Fleet. Copyright 2011 National Public Radio. To see more, visit http://www.npr.org/.