"A limited coalition force entered Aden and another force is on its way" to the southern port city, said the official who requested anonymity.

A figure loyal to Abedrabbo Mansour Hadi told AFP that the force "will start helping us in fighting" the houthi fighters.

The Saudi-led coalition has been conducting air war against popular forces of Yemen from March 26 but this is the first reported ground deployment inside the country.

39 day after Saudi aggression, civilian death toll surpassed 3500. Saudi Arabia launched its bombing campaign against Yemen on March 26 in an attempt to restore power to fugitive President Mansour Hadi, a staunch ally of Riyadh.

Hadi stepped down in January and refused to reconsider the decision despite calls by Ansarullah revolutionaries of the Houthi movement.

Despite Riyadh's claims that it is bombing the positions of the Ansarullah fighters, Saudi warplanes are flattening residential areas and civilian infrastructures.

On April 21, after four weeks of bombings, Riyadh declared end to military operations in Yemen, but Saudi warplanes are still bombing residential areas across the war-ravaged nation one week after.