Last Updated May 3, 2015 4:15 PM EDT
SANAA, Yemen - With helicopter gunships hovering overhead, at least 20 troops from a Saudi-led Arab coalition, including Yemeni expatriates, came ashore Sunday in the southern port city of Aden on what military officials called a "reconnaissance" mission, as fighting raged between Iranian-backed Shiite rebels and forces loyal to the nation's exiled president.
The landing was the first of its kind since the start of the Saudi-led air campaign against the rebels and their allies - forces loyal to ousted President Ali Abdullah Saleh - who have captured most of northern Yemen and marched on southern provinces over the past year.
The objective of the landing was not immediately clear, but Yemeni military officials said the coalition troops would attempt to better organize and train forces loyal to the country's internationally recognized leader, President Abed Rabbo Mansour Hadi, as well as identify an area that could serve as a "green zone" from which Hadi and his government could operate when they return to Yemen.
At the top of that list, said the officials, is the al-Bureqah area west of Aden, which stretches for about about 10 miles along the coast and is home to a major oil refinery and large fuel tanks.
The Western-backed Hadi fled Aden to neighboring Saudi Arabia in March, just a few weeks after he fled the capital, Sanaa, which was captured by the rebels, known as Houthis, in September.
Saudi officials declined to immediately comment on Sunday's landing. However, military and security officials have repeatedly said a ground operation would follow the Saudi-led air campaign that began March 26, after the military capabilities of the Houthis and their allies had been sufficiently weakened.
On Sunday, the Yemeni officials said that streamlining the militiamen fighting the Houthis in Aden was a key step toward establishing a coherent force that a coalition expedition in Aden could lend support to.
The coalition troops, who included black-clad masked men as well as Yemeni expatriates wearing military-style shorts, landed in a central area between Aden's neighborhood of al-Mansoura and the airport, said the Yemeni officials and witnesses reached by The Associated Press inside Aden. They said helicopter gunships hovered above the landing area as the troops came ashore.
The officials, who include a top army commander based in Aden and loyal to Hadi, spoke on condition of anonymity as they weren't authorized to brief journalists. Residents who witnessed the landing also spoke on condition of anonymity for fear of reprisals.
The troops used at least four vehicles to move around Aden and included Yemenis who had been serving in the armed forces of Gulf Arab members of the coalition and were likely serving as guides, the officials said.
They said the troops carried assault rifles, took photos of the areas they toured and carried topography equipment. There was no precise figure available for their number, the nationality of the non-Yemenis among them or how long they intended to stay. It was not immediately clear whether they were ferried to Aden by helicopters taking off from coalition navy ships off the coast of Yemen or traveled to shore in speed boats.
They landed amid a surge in coalition airstrikes against positions of the Iranian-backed Houthis and their allies in Aden, including those at the city's airport.
The landing came one day after Egyptian President Abdel-Fattah el-Sissi discussed Yemen with the Saudi leadership during a brief visit to the oil-rich kingdom. Egypt, the most populous Arab state, is a key member of the coalition and has been touted as a likely participant in any ground operation in Yemen.
Details of the talks have not been disclosed by Cairo or Riyadh.