Sana’a and Riyadh, Asharq Al-Awsat—A joint military operation to liberate the central Yemeni province of Ma’rib from Houthi rebels began at dawn on Sunday, according to Yemeni military sources.

Speaking to Asharq Al-Awsat, the sources said forces from the Yemeni army and volunteers loyal to Yemen’s President Abd Rabbuh Mansur Hadi, backed by ground troops and air cover from the Saudi-led anti-Houthi coalition, have begun the most “comprehensive and violent” assaults on Houthi positions in the central province since coalition troops began arriving there in August.

Local sources told Asharq Al-Awsat airstrikes by Apache helicopters and F-16 fighter jets as well as heavy weapons such as tanks and Katyusha rocket launchers have been used by the coalition as part of the offensive.

Dozens of Houthi fighters have fallen since the operation began, with many more fleeing their posts and at least 15 taken hostage by coalition troops, they said.

The operation to liberate the central province from the Houthis and ally fighters loyal to ousted former president Ali Abdullah Saleh is seen as a precursor to another assault, aiming to retake the capital Sana’a from the Houthis.

The ground operation for Sana’a will see coalition troops and Hadi loyalists head to the capital following the liberation of Ma’rib and then the Saada and Al-Jawf provinces. The three areas lie to the north, east, and northeast of the capital respectively.

This comes as thousands of coalition forces have rolled into Ma’rib in recent weeks, including Qatari and Emirati forces.

The Saudi-led coalition’s campaign began in March following a coup by the Houthis that dislodged President Hadi and his government from power. This followed the group’s takeover of Sana’a in September 2014 and their spread across other areas of the country.

The coalition campaign initially targeted Houthi positions via airstrikes, supporting ground offensives by Hadi loyalists. The campaign has thus far liberated most of the country’s southern regions, including the strategic port city of Aden, from the Houthis and their allies.

However, the current operation marks the first time ground troops from the coalition will be used in a coordinated operation with Hadi loyalists.

Meanwhile, President Hadi, currently residing in exile in Saudi Arabia, on Sunday rejected calls for dialogue with the Houthis unless they accepted a UN resolution stipulating they withdraw from all areas under their control and return all seized weapons back to the state, a statement from his office said.

Hadi is due to return to Yemen for the first time since March, when the Houthi coup forced him to seek exile in Saudi Arabia, and will visit Aden on the Muslim Eid Al-Adha holiday, which will fall on September 23.

Fahd Al-Zayabi contributed additional reporting from Riyadh.