ADEN, Yemen, July 8 (Xinhua) -- Warplanes of the Saudi-led Arab coalition launched an airstrike and mistakenly killed five pro-government fighters in Yemen's western port city of Hodeidah on Sunday, a military official told Xinhua.

The Saudi-led airstrike targeted by mistake a gathering of the Giants Brigade in Hodeidah's district of Tuhyata, killing at least five fighters at the scene, local military official said on condition of anonymity.

"Friendly fire killed five of our fighters who were securing the liberated areas after hours of expelling the Houthis from the same place," the military source said.

The Giants Brigade fighters advanced in the ongoing fighting against Houthis in Tuhyata and the surrounding areas, according to the source.

Meanwhile, fierce fighting continued between the Yemeni government forces, supported by the United Arab Emirates (UAE), and the Iranian-backed Houthis in different areas of Hodeidah.

Warplanes of the Saudi-led Arab coalition targeted Houthi-controlled sites in Hodeidah with a number of airstrikes, causing casualties.

The Houthi leaders reportedly rejected a UN proposal to withdraw from Yemen's Hodeidah city and port voluntarily without fighting. The Houthis have instead proposed that the city should be under joint governance with the UN.

On June 13, the Arab coalition, backing internationally-recognized government of Yemen's President Abd-Rabbu Mansour Hadi, declared a major assault to recapture Hodeidah and the Yemeni western Red Sea coast from the Houthis.

Yemen's government and Saudi Arabia have repeatedly accused the Houthis of using the port to smuggle Iranian weapons. Both Houthis and Iran denied the accusation.

Humanitarian agencies have warned of any attack on the port, saying it would lead to the world's biggest humanitarian catastrophe in modern history.

Hodeidah is the most important point of entry for food and basic supplies to Yemen's northern provinces controlled by Houthis, including the capital Sanaa.

More than 121,000 residents have fled the city of Hodeidah and other parts of the province since June 1, the UN said this week.