Three suicide bombings on Friday struck checkpoints of Yemeni loyalist forces in Aden, killing 22 people, including 10 civilians, a security official said.

Two bombs went off simultaneously at separate checkpoints in Shaab district, on Aden's western outskirts, before gunmen attacked a nearby base of the Saudi-led military coalition, the official said.

Apache helicopters belonging to the coalition attacked positions of gunmen in the surrounding area as fighters attempted to advance toward the base.

A third explosive device planted in an ambulance was detonated at checkpoint near Mansura, in central Aden, the official said.