SANAA (Dispatches) -- Saudi and Emirati-backed forces began an offensive on the Yemeni port city of Hudaydah early on Wednesday, despite warnings from Western governments and international aid groups about the catastrophic effect the battle could have on humanitarian conditions in the country.
Warplanes and battleships belonging to Saudi Arabia and the UAE backing those loyal to former president Abd Rabbuh Mansour Haid battered the fortifications of Houthi fighters and their allies in the Yemeni army in the key port city.
According to reports, an Emirati warship was hit by the defending Houthi forces, with another battleship pulling out of the fray as a result.
Field commanders announced the beginning of the ground assault, after reinforcements swelled the ranks of mercenaries and Hadi loyalists around Hudaydah.
As of Wednesday afternoon, Hadi loyalists had reportedly advanced to around five kilometers of al-Hudaydah's airport and clashes were ongoing between the two sides.
The Houthis and their allies have sent fighters and vehicles from various parts of Yemen to reinforce their forces and are prepared to confront any attempts by the mercenaries as they advance towards the city, Houthi leader and political analyst Muhammad al-Dailami told Middle East Eye.
"Hudayday is a main front and it is the only port to Yemenis, so there is no way that (the fighters) will abandon Hudaydah," Dailami said on Wednesday.
The operation is being led by Tareq Saleh, nephew of former President Ali Abdullah Saleh, who was killed by the Houthis after turning on them.
Aid group CARE international said 30 airstrikes had hit the city on Wednesday morning.
"Some civilians are entrapped, others forced from their homes. We thought it could not get any worse, but unfortunately we were wrong," CARE's acting country director, Jolien Veldwijk, said.
The United Arab Emirates, the key Saudi ally in the invasion of Yemen, had set a Tuesday deadline for the Yemenis to withdraw from the city under UN-led negotiations or face an assault. Hadi visited the UAE in a rare move on Tuesday.
Ahmed al-Absi, an employee in a private water station and father of five, said that he had cancelled plans to celebrate the end of Ramadan as a result of the operation.
"Safety is more important than anything else, so instead of preparing to receive Eid, residents are preparing very well to save themselves from the coming battles in the city," he told Middle East Eye.
"Some residents decided to live in the basements of their houses, others have already fled Hudaydah, but for me I will travel to Sanaa in the coming days, as I believe this is the best solution to save my family."
Others in the deeply impoverished province are not fortunate.
One street vendor, named Abdul Mageed al-Raimi, said he feared airstrikes would target camps housing displaced residents and that, regardless, he did not have money to flee the city.
"If I flee the city to camps, I will be a target of airstrikes, so I will stay at my house and Allah will protect me and all needy people from the battles," Raimi told MEE.
"We hardly eke out for our families, and instead of providing us with food, warring sides will bring the battles to the middle of the city. I am an illiterate man but I am aware that this is stupid behavior by warring sides."
The United Nations - which has been evacuating staff this week - had warned that an attack on the densely populated city could have catastrophic humanitarian consequences.
"A military attack or siege on Hudaydah will impact hundreds of thousands of innocent civilians," the UN humanitarian coordinator in the country, Lise Grande, said in a statement on Friday.
"In a prolonged worst case, we fear that as many as 250,000 people may lose everything - even their lives."
More than 10,000 people have been killed since Saudi Arabia led a bombing campaign against Yemen. The conflict has also caused a cholera outbreak and brought the already impoverished nation to the verge of famine.
On Monday, the UN Security Council voiced support for diplomatic efforts to avert the attack on Hudaydah.
UN aid chief Mark Lowcock, who also briefed the council, said an attack on the port city would be "catastrophic" and that aid agencies were hoping to "stay and deliver" in Yemen, which the UN describes as the world's worst humanitarian crisis.
Yemen relies on imports for 90% of its food, and 70% of those transit through Hudaydah, Lowcock said.
Eleven humanitarian aid agencies, including Oxfam and Save the Children, separately wrote to British Foreign Secretary Boris Johnson earlier this week urging him to warn Saudi Arabia that it will lose British support if it attacks Hudaydah.
"If an attack does take place, casualties on all sides will be high, with a likely catastrophic impact on the civilian population," they wrote.
Abu Dhabi's critics say the UAE military operations have focused on port cities to control commerce in the strategic region, not to drive out the Houthis.