ADEN (Reuters) - A Salafist imam was shot dead by gunmen early on Saturday in Aden, southern Yemen, witnesses and local officials said, the third killing of a Salafist imam this month.

Sheikh Adel Al Shehri, imam of a mosque in Inmaa district west of Aden, was shot while he was heading to the mosque for morning prayers.

No one has claimed responsibility for the three killings and no motive has been made clear, but some of the ultra-conservative Salafists back secession for southern Yemen, and have been a major component of the breakaway southern army.

A former Aden governor has declared a council that seeks secession for southern Yemen. A referendum on independence would be announced soon, he said.

Aden is also dominated by local forces backed by the United Arab Emirates - a key member of the Saudi-led coalition that intervened in Yemen’s civil war in 2015 to restore President Abd-Rabbu Mansour Hadi to power but which are hostile toward Islamists.