The concept of a federal state in Yemen loomed large as Yemeni politicians and tribal leaders met in the Saudi capital Riyadh to seek a formula for a lasting peace.

The three-day conference, opened on Sunday under the theme “Saving Yemen and Building a Federal State”, has brought together more than 400 delegates, but Al Houthi rebels were not represented after they insisted that the meeting be held in Yemen.

Meanwhile, the Saudi-led coalition bombing Yemen on Monday blamed ceasefire violations by Al Houthis for the resumption of air strikes against them.

“They did not respect the humanitarian pause. That’s why we do what is necessary to be done,” Brigadier General Ahmed Al Assiri said.

“There is an operation in process.”

The coalition resumed the bombing an hour after the five-day truce ended at 2000 GMT on Sunday.

The pause was proposed by Saudi Arabia to allow urgently needed humanitarian aid into Yemen.

“These militia did not stop their fighting. They continued to attack borders, to attack cities in Yemen,” Assiri said, adding there was “a very big change on the ground” during the pause.

Asked about the possibility of another truce, Assiri said: “When we talk about ceasefire it should be a negotiation between two parties but those militia, since 2216, reject everything.”

He was referring to a UN Security Council resolution which in April imposed an arms embargo on the rebels and demanded they relinquish seized territory.

The invitation to the Riyadh conference was extended to all parties with the condition of recognising the legitimacy of President Abd Rabo Mansoor Hadi and his government.

“We want you to rise to the historic and exceptional responsibilities to rescue the nation and the citizens, recuperate the state and its institutions and build the new federal Yemen that we all dream to have,” President Hadi told the delegates. “The new federal Yemen will be built on the values of justice and equality and will be founded on order and law. Do not waste your time discussing marginal issues, particularly that your people are painfully suffering,” he said.

As the Yemeni president referred to the significance of federalism in the new Yemen, Saudi daily Al Sharq Al Awsat on Monday reported that the Riyadh Document discussed by the participants in the conference, would highlight the importance of security and stability in Yemen.

The document will be based on essential principles that include commitment to constitutional legitimacy and the establishment of a federal state based on security and stability in Yemen, the daily said.

Essential references for the Riyadh Document will be the Gulf Cooperation Council (GCC) initiative, the outcome of the National Dialogue Conference, UN resolution 2216, the 2015 Arab League Resolution on Yemen, the GCC declarations and the letters by President Abd Rabo Hadi to the GCC, Arab League and United Nations Security Council in March.

Federalism had emerged as a strong option to solve the challenging political crisis that hit the country and pitted the north against the south, two separate states until they were reunited in 1990.

The option was discussed by the participants in the National Dialogue Conference (NDC) that brought together representatives from across the country to determine Yemen’s political future.

However, after months of negotiations, the NDC agreed on a six-region federal system that would pacify marginalized groups demanding independence, particularly in the south, but the real challenge remained in how to implement practically the new multistate system of government and how to divide authorities at the local, regional, and federal government levels.

In 2013, Yemeni researcher Nabeela Ghaleb said that federalism as an advanced political and administrative system in Yemen would be welcomed by politicians, but insisted that the country needed to work on the required political foundations and experiences for the system.

- with inputs from AFP