envoy to yemen jamal ben omar has resigned. the u.n. has said ben omar has expressed his desire to move on to another assignment. the war is increasing to intensify. it has been three weeks since saudi arabia began air strikes against houthi rebels. ben omar has warned the council that yemen was slipping towards a civil war. he was appointed in april 2011. he has been with the u.n. in various positions and before he was in yemen he was a political prisoner in his home country of morocco. ben omar's resignation was on the cards yemen officials were unhappy with his handling of the conference. >> national dialogue conference the u.n. was supposed to support everything that is happening in that dialogue. he was supposed to be the main mediator with yemen's political allies all on the ground. but what he did instead he is chap roand a process that was chaperoned a process that was all, a bureaucratic exercise of good governance with nothing being implemented on the ground. analysts and others like myself, have said, the salaries went to all

s envoy to yemen jamal ben omar resigns. the conflict shows no sign of ending. i'm nick clark live from our headquarters in doha. also coming up. colombia resumes strikes against farc rebels. >>> and a year after the ferry tragedy in south