ADEN (Reuters) - An aid worker from the United Arab Emirates was shot dead in the southern Yemen city of Aden by unknown gunmen on Saturday, a Yemeni security officer said, in another sign of instability in the port city where Yemen’s fragile government is based.

“The aid worker was traveling in an armored land cruiser with a group of Emiratis in Aden’s Mansora district. He was shot dead when he exited the vehicle near a store by gunmen pursuing in another car,” said the official.

A UAE spokesperson was not available for comment.

Al Qaeda and Islamic State have both gained ground in Yemen, where a war has been raging for seven months between a Saudi-led military alliance and Houthi militiamen allied to Iran.

In a series of suicide bombings on Oct. 6, Islamic State killed 22 people, including several troops from the United Arab Emirates, at the government headquarters in the southern port of Aden and military bases in the city.

It was the biggest attack on the government and its coalition ally since Gulf Arab and Yemeni troops retook the city from its Houthi forces in July.

Two Red Cross aid workers were shot dead in the northern Yemeni province of Amran in September by unknown gunmen.

Ground fighting and Saudi-led air strikes have killed at least 5,400 people in Yemen’s multi-sided conflict, which started as a civil war among competing factions but has drawn in outside powers in a regional struggle for influence between Sunni Gulf countries and Shi’ite Iran.

The Yemeni government returned from exile in Saudi Arabia and set up temporary headquarters in Aden’s al-Qasr hotel last month.