Yemeni security officials say that suspected militants have gunned down a senior security official in the southern city of Aden.

The officials say that gunmen shot to death Col. Ali Awwad, head of intelligence in the Buraqa district as he was leaving his house on Friday and fled the scene on a motorbike. The killing comes less than 24 hours after suspected militants killed another top security official at the Aden airport.

The Islamic State affiliate in Yemen claimed responsibility in Twitter postings.

The officials spoke on condition of anonymity because they were not authorized to speak to the press.

Aden slid into lawlessness in the months that followed the expulsion of Shiite rebels and their allies last year by the internationally-recognized Yemeni government's backers, a Saudi-led military coalition.