Jamaicans voted Thursday in elections marred by violence and in which socialist leader Michael Manley was heavily favored to defeat conservative Prime Minister Edward Seaga, a staunch U.S. ally. Police spokesmen said a pregnant woman was killed and four people were wounded, one of them seriously, in separate, election-related incidents after the polls opened for Jamaica's first contested elections in eight years. The woman was shot and killed as she followed an unidentifed candidate down a central Kingston street with a group of party supporters, police said. The gunmen escaped.