ADEN, Yemen, May 12 (Xinhua) -- One police officer was killed and five others were injured on Saturday in a fresh attack on a police patrol in Yemen's southern port city of Aden, an Interior Ministry official told Xinhua.

The Interior Ministry source, who asked to remain anonymous, said that some five policemen were also injured when their patrol was ambushed by unknown gunmen in Aden's neighborhood of Mansourah.

The condition of the injured were critical and shifted to nearby hospitals for treatment, the source said.

According to the source, the attackers also suffered casualties during the clash with soldiers, but their number could not be exactly specified.

Such armed attacks and ambushes are common in the Yemeni southern regions, especially in Aden, where various military factions backed by the Saudi-led coalition are deployed.

The southern port city of Aden is considered as Yemen's temporary capital and the Saudi-backed Yemeni government based itself there since 2015.

During the past two years, the al-Qaida in the Arabian Peninsula (AQAP) and other terrorist groups including the Islamic State had an active presence in Yemen's southern part.

The impoverished Arab country has been locked into a civil war since the Iranian-backed Shiite Houthi rebels overran much of the country militarily and seized all northern provinces, including capital Sanaa, in 2014.

Saudi Arabia leads an Arab military coalition that intervened in Yemen in 2015 to support the government of President Abd-Rabbu Mansour Hadi after Iran-backed Houthi rebels forced him into exile.

The United Nations has listed Yemen as the world's number one humanitarian crisis, with seven million Yemenis on the brink of famine and cholera causing more than 2,000 deaths.