MARIB: Loyalists and Iran-backed rebel fighters have clashed on several fronts in Yemen, officials said on Tuesday, the second day of a UN-brokered ceasefire the insurgents have warned is in jeopardy. Forces loyal to President Abedrabbo Mansour Hadi fought with Shiite Huthi rebels in the province of Marib, east and north of the rebel-held capital Sanaa, officials said. The rebels and their allies loyal to ousted president Ali Abdullah Saleh advanced overnight in the area of Sarwah, in Marib, wresting control of two hills, a military official said. The Saudi-led coalition, which launched a military campaign against the rebels last year, had described violations on Monday as “minor”. Seven soldiers have been killed and 15 others wounded in Sarwah in rebel attacks since the ceasefire entered into force at midnight between Sunday and Monday, the official said.