Somali leaders have approved a new constitution, as the country approaches a U.N. deadline for completing its government transition.

An assembly that began working last week in Mogadishu overwhelmingly approved the document Wednesday.

The meeting came as a pair of suicide bombers tried to attack the area. Authorities said the bombers were killed, but at least one detonated explosives. A Somali security officer was also wounded.

No group immediately claimed responsibility for the attack, but Somalia has long battled al-Qaida-linked al-Shabab militants.

The U.N. Security Council said last week that the transition is at a “decisive phase” and must be completed by August 20. Somalia must still select a new parliament and elect a new president.

Somalia's Transitional Federal Government has been in place since 2004. It has been unable to assert power because of chronic infighting and chaos in the country.