UN envoy Martin Griffiths on Thursday described "dangerous signs" that a Houthi-rebel assault in Yemen's oil-rich Marib province was growing fiercer and called for a Ramadan respite to the fighting.
Mr Griffiths said the “major centre of gravity” in Yemen’s six-year civil war was Marib, the capital of an oil-rich region and the Saudi-backed government’s last strategic pocket of territory in the north.
“The fighting in the area is showing dangerous signs of escalating once again,” Mr Griffiths told the UN Security Council.
“Internally displaced people, along with local communities, have been in the line of fire.”
He also described worsening violence around the southern city of Taez, where civilians are on the front lines of fighting as they also tackle an "alarming resurgence" of coronavirus.
The council met hours after Saudi Arabia reported intercepting five missiles and four armed drones launched by the rebels towards the southern Saudi city of Jizan, with falling debris causing a small fire at Jizan University.
Mr Griffiths said he was “alarmed by reports of multiple drone and ballistic missile attacks”, some of which have struck civilian buildings.
Yemen’s conflict has claimed some 233,000 lives and pushed the country to the brink of famine in what the UN calls the world’s worst humanitarian emergency.
Fighting began in 2014 when the Iran-aligned Houthis seized the capital Sanaa and pushed out the internationally recognised government.
A Saudi Arabia-led coalition intervened militarily the next year to restore that government with an air bombing campaign that has been criticised for causing mass civilian casualties.
US President Joe Biden ended support to Riyadh’s war and launched a diplomatic offensive to end the devastating war that has yet to gain traction.
“The urgency of progress towards a peaceful settlement makes the continued violence on the ground all the more concerning,” said Mr Griffiths.
Mr Griffiths was on Wednesday in Abu Dhabi for talks with Aidarus Al Zubaidi, president of Yemen's Southern Transitional Council, and senior UAE officials, as part of renewed efforts to cut a political solution to end the six-year conflict.
The UN's head of humanitarian affairs Mark Lowcock said 360,000 doses of Covid-19 vaccines reached Yemen this month, but shots were not arriving fast enough to halt the fast-spreading pathogen.
"The second wave is coming at a time when large-scale famine is still bearing down on the country," said Mr Lowcock.
"Tens of thousands of people are already starving to death with another five million just a step behind them."
