Clashes between rebels and Yemeni government fighters have killed at least 111 people in Marib in three days, pro-government sources said, following a new attack by Houthi rebels. Iran’s allied rebels have stepped up their efforts to seize Marib, the government’s last stronghold in northern Yemen, in February, and fighting has killed hundreds on both sides. Clashes between Thursday and Sunday killed 29 pro-government staff and at least 82 insurgents, three pro-government sources told AFP. The revolutionary forces have not confirmed the tolls. The Yemeni conflict erupted in 2014 when the Houthis occupied the capital Sanaa, prompting Saudi intervention to support the government next year.