SANAA, Yemen -- Yemeni medical officials said the Saudi-led coalition fighting Yemen's Shiite rebels conducted airstrikes in the rebel-held port city of Hodeida on Thursday, killing at least 28 people and wounding 70. But the coalition denied carrying out any attacks in the city.

The airstrikes took place close to the city's main public hospital, al-Thawra, and near a popular fish market, the officials said. The wounded, mostly civilians, were hospitalized. The medical officials spoke on condition of anonymity because they were not authorized to brief the media.

Rebel-run Al Masirah TV reported that airstrikes killed 52 people and left more than 100 wounded.

The coalition's spokesman, Col. Turki al-Malki, told the Saudi-owned Al Arabiya satellite news channel that it didn't carry out any attacks on Hodeida and blamed the attacks on the rebels, known as Houthis. He said the coalition "follows a strict and transparent approach based on the rules international law."

Ahmed Yehia, who witnessed the attack, said body parts were scattered in the area of the strike.

"There is a pond of blood outside the hospital's building," he said.

The Saudi-led coalition backing Yemen's internationally recognized government has sought to expand control over rebel-held areas along Yemen's west coast, particularly in the vital Red Sea port city of Hodeida, the main entry point for food in a country teetering on the brink of famine. The coalition has been at war with the Iran-aligned Houthis since March 2015.

U.N. Special Envoy Martin Griffiths has held talks with both sides in recent weeks in the hopes of preventing a full-scale coalition assault on Hodeida. He has been pushing to bring the warring parties to restart peace talks. Yemen's government maintains that the rebels' "unconditional withdrawal" from Hodeida is key to restarting the talks. Houthis have long refused to hand over the city.

Later on Thursday, Griffiths announced plans to invite Yemen's warring parties to Geneva on Sept. 6 to hold the first round of consultations.

He said on his official Twitter account that the consultations "will provide the opportunity for the parties to discuss the framework for negotiations, relevant confidence-building measures and specific plans for moving the process forward."

The three-year stalemated war has killed over 10,000 people, badly damaged Yemen's infrastructure and crippled its health system. The country is now in the world's worst humanitarian crisis, with more than 22.2 million people in need of assistance.