At least 40 soldiers were killed in Yemen on Sunday after a suicide bomber blew himself up in Aden. Dozens more were injured at the gathering near Solban army base in northeastern Aden, according to military officials and medics.

The base was targeted by a suicide bomber last week in an attack that killed 48 soldiers and wounded 29. That attack was claimed by a Yemeni affiliate of the “Islamic State” (IS) extremist group.

No group has yet claimed responsibility for Sunday’s bombing, though IS and al-Qaeda are both active in the country.