(France 24: 0844 PST, April 18, 2011) Tension simmered in Yemen on Monday after a fruitless meeting with Gulf mediators and violent late-night demonstrations in Sanaa. The streets of the capital appeared quiet on Monday following overnight clashes with security forces. Late on Sunday, hundreds of thousands of men and women protested against President Ali Abdullah Saleh's call for an end to men and women demonstrating together against the regime, and called for his departure.