Protesters march in Congo Republic capital for second day

BRAZZAVILLE (Reuters) - Security forces fired warning shots to try to disperse hundreds of protesters marching in Congo Republic's capital Brazzaville on Wednesday against a referendum on lifting presidential term limits. At least four people were killed on Tuesday when police opened fire on a crowd of opposition supporters. President Denis Sassou Nguesso's critics accuse him of seeking to use Sunday's referendum to extend his rule ahead of a 2017 election. (Writing by Emma Farge; Editing by Cat