Four people including three militants were killed in an attack overnight on the presidential palace in Mogadishu. The attackers used car bomb explosion and gunfire during the assault.
The attack was the latest in a series of attacks by Al Shabaab against Somalia's political institutions, Dujarric said at a daily news briefing here, quoting Kay.
After meeting the president and prime minister of Somalia, special representative Nicholas Kay said the political progress in Somalia was only possible through the unity of its political institutions, and the unity was being attacked by those determined to plunge the country back into turmoil, according to the spokesman.
Dujarric said that Kay reiterated the UN's support for the people and institutions of Somalia as they make progress towards stability and peace.
Islamist al-Shabaab militants claimed responsibility for the attack.