Arab coalition forces on Monday continued air, sea and ground bombardment on Iranian-allied Shiite Houthi rebels in Yemen's Red Sea port city of Hodeidah. The coalition, led by armies of Saudi Arabia and United Arab Emirates (UAE), launched major assault six days ago aiming at capturing the city's strategic airport in the southern edge of Hodeidah. Human rights activist Adel Bishr of local independent Al-Saleh Charity Foundation told Xinhua that the ground battles were still centered in Manzara village along the Red Sea shore, around 10 km southeast of the airport. Houthi fighters using AK-47 Klashnikov rifles have strongly fought back, and blocked several advancing attempts by the coalition forces, Bishr said. "The airport and all its gates and main roads around it are still under control of Houthi fighters," said Bishr who along with a 10-member team travelled from Sanaa to Hodeidah last week for a humanitarian task, reported Xinhua news agency. He said the situation inside the city is relatively calm, but the coalition warplanes have conducted tens of air strikes on the airport, "causing panic among the residents." Houthi-run al-Masira television reported six air strikes hit al-Durayhemi district and areas around the airport. It said one air strike hit a house in the district, killing four men and a woman. On Sunday, the television reported 26 air strikes on the airport. The whole port city of around 600,000 people is still under the control of Houthi fighters, according to Bishr. "Houthi fighters have cut off the Kilo 16 Road linking Hodeidah downtown to the highway leading to the capital Sanaa, and set up dozens of military checkpoints," Bishr said. Nearly 3,000 people had fled Manzara and al-Durayhemi district to schools inside Hodeidah city and some others managed to escape to mountainous districts far away. "I heard from some of the displaced families that they saw dozens of dead fighters from both rival forces lying on the streets in Manzara and along the road leading to the airport," Bishr said. The coalition said it has gathered 20,000 soldiers for the most major battle since more than three years of war, and there will be swift and clean assault to seize the air and sea ports. Houthi media reported that they have dispatched 4,000 fighters in pick-up vehicles for defending the port city. Meanwhile, UAE Minister of State for Foreign Affairs Anwar Gargash told a news conference in Dubai that the coalition forces' offensive in the Yemeni western coast, which leads by his country's forces, are taking into account the humanitarian situations and the population. "Our approach is methodical, gradual to pressure Houthis to do the right thing, which is basically the decision to withdraw unconditionally," Gargash said. Gargash said the coalition leadership is in contact with Martin Griffiths, the UN special envoy for Yemen, to secure a deal with Houthi to retreat from Hodeidah. Griffiths arrived in Yemen's rebel-held capital Sanaa on Saturday, in renewed effort to stop the fighting in Hodeidah. It is the second official visit to Sanaa by Griffiths in two weeks. Griffiths stressed that the UN is determined to press ahead with the political process to halt the ongoing fighting in the southern port city of Hodeidah, according to the Houthi media reports. On Monday, Griffiths met with Houthi top official Mahdi al-Mashat to discuss the possibility of stopping the war, the rebel-controlled Saba news agency reported, but it provided no further details. Griffiths is expected to leave Sanaa on Tuesday, according to a Houthi official, who spoke on condition of anonymity. International humanitarian agencies have warned that an assault on Hodeidah would be a major disaster to the densely populated port city and would block aid supplies to more than 20 million people. Hodeidah is the only lifeline route of supplying imports and humanitarian aid to the northern Yemen. The Saudi-led coalition intervened in Yemen in March 2015. The war has killed over 10,000 people, mostly civilians, and forced 3 million others out of their homes.