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Convoy of the UN special envoy to Yemen Martin Griffiths leaves the Sanaa International Airport after the envoy arrives in Sanaa, Yemen, May 5, 2019. The UN Special Envoy to Yemen Martin Griffiths arrived in the capital Sanaa on Sunday, in attempt to push the Houthi rebels to implement a peace agreement last year. (Xinhua/Mohammed Mohammed)

SANAA, May 5 (Xinhua) -- The UN Special Envoy to Yemen Martin Griffiths arrived in the capital Sanaa on Sunday, in attempt to push the Houthi rebels to implement a peace agreement last year.

Houthi TV al-Masirah reported that Griffiths would meet leaders of the rebel group to discuss the peace process.

Journalists were not allowed to meet the envoy in Sanaa.

Griffiths has been shuttling between the Iranian-allied Houthi rebels in Sanaa and the exiled Yemeni government in the Saudi capital Riyadh to end more than four years of civil war, which erupted after the rebels seized much of the country's north in late 2014.

Griffiths' Sunday visit to Sanaa was the second in fewer than a month.

Rebel-held territory, including Sanaa, has endured a regular blackout and severe shortages of food, medicine and fuel since 2015.

A peace deal reached between Yemeni warring parties in December last year has hit a deadlock.

The deal, first step toward a comprehensive political solution, focused on the port city of Hodeidah, the lifeline for Yemen's most commercial imports and humanitarian aid.

Both warring parties have largely obeyed the cease-fire deal, but have failed to withdraw forces from the city.