High-ranking officials in Yemen's port city of Aden say al-Qaida militants have taken control of key areas of the city.

They said Saturday the fighters have seized the Tawahi district entirely and were patrolling the streets. The area is home to a presidential palace and a port.

The officials, who hail from the military, security forces and police, spoke on condition of anonymity because they weren't authorized to speak to journalists.

Al-Qaida's Yemen branch is considered by Washington to be the most dangerous offshoot of the terror network.

Yemen's conflict pits the Iran-allied Houthis and troops loyal to the former president, Ali Abdullah Saleh, against an array of forces including southern separatists, local and tribal militias, Sunni Islamic militants as well as troops loyal to President Abed Rabbo Mansour Hadi.