Displaced Yemenis sit in their shelter at a makeshift camp for displaced people in the Haradh area, in the northern Abys district of Yemen's Hajjah province, on Wednesday (AFP photo)

MAARIB/GENEVA — A total of 27 journalists have been killed since the outbreak of Yemen’s civil war in 2014, the Yemeni Journalists Syndicate, an NGO, said on Saturday, according to the Anadolu Agency.

“The press freedom [in Yemen] is going through very difficult conditions and has been subject to a systematic war since 2014," the syndicate said in a statement marking the Yemeni Press Day, which fell on Saturday.

According to the statement, a total of 27 journalists “have lost their lives for the sake of fulfilling the right of the society to obtain information”.

The syndicate said media outlets in Yemen have been looted, journalists and photographers chased and hundreds of news portals blocked.

It called for the release of 12 journalists held by Houthi rebels and another journalist taken hostage by Al Qaeda militants, Anadolu reported.

Separately on Friday, a a senior UN humanitarian officials said that a long-anticipated assault on Yemen's port city of Hodeidah by the Saudi-led coalition could cost up to 250,000 lives, Reuters reported.

A coalition spokesman said on Tuesday that allied forces were 20km from Houthi-held Hodeidah, but he did not specify whether there were plans for an assault to seize the port, the chief entry point for food and supplies needed to ease a famine and cholera epidemic.

Humanitarian agencies working in Yemen are deeply worried by the likely impact of an assault. As many as 600,000 civilians currently live in and around Hodeidah, which lies on Yemen's Red Sea coast, the United Nations said.

"A military attack or siege on Hodeidah will impact hundreds of thousands of innocent civilians," the UN humanitarian coordinator in the country, Lise Grande, said in a statement, according to Reuters.

"In a prolonged worst case, we fear that as many as 250,000 people may lose everything — even their lives."

Coalition officials could not immediately be reached for further comment.

Senior aid officials have urged the United States and other Western powers providing arms and intelligence to the coalition to push the mostly Sunni Muslim Gulf Arab allies to reconvene UN talks with the Iran-allied Houthi movement to avoid a bloodbath and end the three-year-old war.

The United Nations says Yemen is the world's worst humanitarian crisis and 22.2 million Yemenis are in need of humanitarian aid, and 8.4 million are at risk of starvation, a number that will rise to 18 million this year if conditions do not improve.

Yemeni political sources have said the UN Yemen mediator, Martin Griffiths, is in talks with the Houthis to hand over control of the port to the United Nations in an attempt to avert a possible assault.

The broader UN peace plan calls on the Houthi movement to give up its ballistic missiles in return for an end to the bombing campaign against it by the Saudi-led coalition and a transitional governance agreement, according to a draft document and sources.

The International Committee of the Red Cross said on Thursday it had pulled 71 international staff out of Yemen because of security incidents and threats, moving them to Djibouti.