MINYA, March 25 (Reuters) - Police fired tear gas to disperse demonstrations on Tuesday over mass trials of Muslim Brotherhood members in the southern Egyptian town of Minya, a Reuters witness said.

About 700 people held protests at Minya University after the leader of the Brotherhood and 682 others went on trial on charges including murder, a day after more than 500 supporters of deposed Islamist president Mohamed Mursi were sentenced to death. (Writing by Michael Georgy; Editing by Hugh Lawson)