A roadside bomb blast in Somalia's self-declared republic of Somaliland has killed four people, including an infantry division commander.

Two remote-controlled bombs were used in the attack that killed senior security officer, Osman Yusuf, in Somaliland, the region's defense minister, Saleban Warsame Guled, said on Sunday.

After the first blast shook the northern Somali town of Lascanood, Yusuf went to the attack site to investigate. A second explosion then occurred, killing the top commander.

Five others were injured in the blast that blanketed the site with shrapnel and smoke.

Lascanood is an area that both Somaliland and the neighboring semi-autonomous state of Puntland, lay claim to.

No one has yet claimed responsibility for the deadly attack, which came only days after the opposition group, al-Shabab, threatened to attack the northwestern region of Somaliland and other countries in the Horn of Africa, including Uganda and Kenya.

Following the threat, Somaliland's leader on Thursday called for war against the group.

Unlike the rest of Somalia, Somaliland -- which broke away from Somalia in 1991 -- has been relatively peaceful.

FF/TG/DT