Updated

Yemeni security officials close to pro-government forces fighting Yemeni rebels say a Saudi-led coalition is bombing rebel positions near the Bab el-Mandeb strait to weaken them in preparation for a ground offensive there.

Security officials close to the rebels, known as Houthis, say Sunday that 13 of their fighters were killed in the airstrikes. The airstrikes took place in areas Houthis control around the strategic Red Sea strait, including the port town of Mocha, which is connected by road to Taiz, Yemen's third-largest city.

Yemen's conflict pits the Iran-allied Houthis and troops loyal to the former president, Ali Abdullah Saleh, against an array of forces including southern separatists, local and tribal militias, Sunni Islamic militants as well as troops loyal to President Abed Rabbo Mansour Hadi.