ADEN: Unknown gunmen shot and killed a senior Yemeni militia leader and four people travelling in his convoy in the southern city of Aden, residents and militia sources said on Thursday.

Assailants in a car and on a motorcycle opened fire on the motorcade of Ahmed al-Idrisi, a top commander in the pro-government Popular Southern Resistance group, while it travelled on a main road in the Mansoura district late on Wednesday.

The attack came days after the assassination of a prominent judge on the same street and the bombing of a party headquarters, underscoring security chaos in the city which is the embattled Yemeni government's temporary capital.

Idrisi's militia is a main ally of a mostly Gulf Arab coalition which has been bombing the Iran-allied Houthi movement based in the capital, Sanaa, in Yemen's north.

The alliance intervened in the country's civil war on March 26 in support of President Abd-Rabbu Mansour Hadi's government, which the Houthis had ejected from Aden.

Saudi Arabia and its allies believe the Houthis are a proxy for their regional arch-nemesis Iran - something the Islamic Republic and the Houthis deny.

Almost 6,000 people have died in the conflict and though southern militias and Gulf ground forces pushed the Houthis out of Aden in July and paved the way for Hadi to return, battle lines across the country have been stalemated for months as a diplomatic resolution remains elusive.

The Gulf-backed administration has struggled to impose its writ on southern regions it holds as Yemen's new branch of Islamic State has mounted several bombing attacks against it and al Qaeda militants maintain a presence.

A senior Aden judge, Jalal Abdullah, was killed on the Mansoura thoroughfare on Tuesday, hours before a bomb detonated at a nearby headquarters of the Islah Islamist party, injuring one person, according to medics.