Arab warplanes and warships pounded Houthi positions in Yemen's Hodeidah on Thursday as a Saudi-led alliance tried to seize the main port in the largest battle of a war that has created the world's worst humanitarian crisis.

Apache attack helicopters bombed a strip of coastal territory near the city's airport, two residents told Reuters on the second day of the battle.

"The fighting is getting close to the al-Manzar area near the airport and people are fleeing in fear," said Mohammed Abdullah, an employee of the Houthi administration in the city.