Saudi-led forces resumed military operations in Yemen yesterday after a five-day ceasefire ended late on Sunday, and Yemen’s foreign minister blamed the Iranian-allied Houthis for failure to renew the truce.

The end of the ceasefire came despite appeals by the UN and rights groups for extra time to allow the delivery of badly needed humanitarian supplies to the country of 25 million, one of the poorest in the Middle East.

“That’s what we said before – that if they start again, we will start again,” Yemeni Foreign Minister Reyad Yassin Abdulla said. He said the coalition was not considering any new ceasefire but would not target air and sea ports needed for aid shipments.

Saudi-led forces conducted three air strikes on Yemen’s northern Saada province yesterday, according to Houthi media, which said Saudi forces had fired 70 rockets and artillery shells into north Yemen.

Saudi-owned al-Arabiya television reported heavy shelling by Saudi forces at Houthi outposts across the border after the fighters fired mortars at an army post in Saudi Arabia’s southern Najran province.

Earlier in the day, residents said that warplanes struck the Houthi-held presidential palace in Yemen’s southern port of Aden as well as groups of militiamen on the western and eastern approaches to the city and the international airport where Houthis and local fighters have been clashing.

Houthi followers raise their weapons as they demonstrate against Saudi-led air strikes in Yemen’s capital Sanaa yesterday.

Saudi Arabia and its Sunni Muslim allies have been conducting an offensive against the Houthis and units loyal to former president Ali Abdullah Saleh for more than seven weeks, saying the rebels are backed by Shi’ite Muslim power Iran.

The campaign has yet to reverse the Houthis’ advance into Aden and along battlefronts across Yemen’s south. A five-day truce that started on Tuesday night halted the air strikes and allowed humanitarian aid into the country.

US Secretary of State John Kerry said yesterday that Washington supported extending the truce, but that manoeuvres by the Houthis made that difficult.

“We know that the Houthis were engaged in moving some missile-launching capacity to the border with Saudi Arabia and, under the rules of engagement, it was always understood that if there were proactive moves by one side or another, then that would be in violation of the ceasefire arrangement,” he said.

Saudi Foreign Minister Adel Al-Jubeir expressed “regret that the truce did not achieve its humanitarian goals” and held the Houthis responsible, in an e-mailed statement.