BBC– Houthi rebels in Yemen have intensified their push to control the port city of Aden, amid reports of troops landing from the sea.
Initial reports suggested the troops were foreign but an adviser to the Saudis, who are leading a coalition against the Houthis, denied this.
He said they could be loyal to deposed president, Ali Abdullah Saleh, who backs the rebels.
Separately, a Saudi border soldier has reportedly been killed by gunfire.
It is the first known Saudi fatality since the coalition began its air campaign against the Houthis.
Also on Thursday, local officials in the port city of Mukalla said al-Qaeda militants had stormed a prison there and freed at least 150 detainees.