MANAMA, Bahrain, March 13 (UPI) -- More than 800 people were wounded in Bahrain Sunday when protesters were attacked, a hospital spokesman said.
Ahmad Alumran of Salmaniya Hospital told USA Today four of the protesters were in critical condition.
More than 5,000 people marched in the capital, Manama, demanding the fall of the monarchy, security officials said.
The Interior Ministry said protesters attacked unarmed policemen trying to dismantle their tent city, and police responded with tear gas.
But Sayed Hadi Almoosawi of the al-Wefaq opposition party said riot police fired rubber bullets. Armed civilians allied with the police also were reported to be involved.
Clashes also were reported at the University of Bahrain, which announced lectures were halted until further notice.
Thousands of students confronted 150 supporters of the monarchy there, CNN reported.
The unrest came as U.S. Defense Secretary Robert Gates was in the city to talk with King Hamad and Crown Prince Salman. Gates told reporters Saturday the royal family was "serious about real reform and moving forward."
Bahrain is the naval base of the U.S. 5th Fleet in the Persian Gulf.
Since demonstrations began, the king announced the government would build 50,000 new houses and double the police force with 20,000 new positions.