ADEN/GENEVA (Reuters) - A Saudi-led coalition launched air strikes on the outskirts of Yemen’s main port city of Hodeidah as heavy fighting resumed days after U.N.-sponsored talks between the warring parties collapsed, military sources and residents said on Wednesday.

A police trooper stands guard as wounded Houthi fighters demonstrate outside the United Nations offices to demand for medical treatment abroad, in Sanaa, Yemen September 12, 2018. REUTERS/Khaled Abdullah

A senior Yemeni source in the coalition told Reuters that the alliance had renewed an offensive to take control of the city from the Iranian-aligned Houthi movement after an attempt to hold peace talks in Geneva was abandoned on Saturday when the Houthi delegation failed to show up.

The renewed attacks on the port city, a lifeline for millions of Yemenis, could put further pressure on U.N. special envoy Martin Griffiths, who has vowed to press ahead with diplomacy.

Yemeni military forces allied with the coalition said the battles outside Hodeidah began on Monday but intensified on Wednesday.

Coalition warplanes launched air strikes on Wednesday near the eastern gate of the city that leads to roads linking it with the capital Sanaa and Taiz province, residents said.

Coalition-backed troops are trying to take control of the main route between Hodeidah and Sanaa in order to cut off supplies to the Houthi-held capital, they said.

“This is a renewal of the offensive to take Hodeidah. Everyone thought Hodeidah is impossible, and we will prove them wrong,” the senior Yemeni coalition source said.

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Brigadier General Sharaf Luqman, a spokesman for the Yemeni armed forces allied with the Houthis, said they had launched attacks against coalition-backed forces on the west coast, Iran’s Tasnim news agency reported on Wednesday.

The Western-backed alliance intervened in Yemen’s war in 2015 to restore the internationally recognized government of Abd-Rabbu Mansour Hadi. Coalition forces retook much of the south before the war, widely seen as a proxy conflict between Saudi Arabia and Iran, bogged down.

The coalition, led by Saudi Arabia and the United Arab Emirates, launched an offensive to seize Hodeidah in June in the largest battle of the conflict, but called it off after little gains to give peace talks a chance.

“The Houthi NO SHOW at the Geneva peace process is further proof that the liberation of Hodeidah is what is needed to bring them to their senses & constructively engage in the political process,” UAE Minister of State for Foreign Affairs Anwar Gargash said in Twitter post.

U.S. Secretary of State Mike Pompeo said in a statement on Wednesday that he had certified to Congress that Saudi Arabia and the UAE were working to avoid harming civilians in Yemen, clearing the way for continued U.S. help for its ally Saudi Arabia.

The United Nations fears an attack on Hodeidah, the entry point for the bulk of Yemen’s commercial imports and aid supplies, could trigger a famine in the impoverished state where an estimated 8.4 million people are facing starvation.

Griffiths is heading to Oman on Wednesday to meet Houthi leaders, and then to Sanaa, his spokeswoman Hoda El-Turk said.

“We want to go to Muscat to find out ... how do we arrange things in a different way so that both parties can sit down together next time around,” Griffiths told reporters in Geneva on Saturday.

Houthi leader Abdul Malik al-Houthi accused the coalition of blocking his movement’s team from traveling to the peace talks. The foreign minister of Hadi’s government, Khaled al-Yamani, accused the Houthis of “trying to sabotage the negotiations”.

The Yemen war has killed more than 10,000 people and displaced more than 2 million, according to the United Nations.