MOGADISHU — A bomb exploded on Monday on a bus carrying UN employees in northern Somalia, killing at least 10 people and wounded many others, police and UN officials said. The Al-Qaeda-linked Al-Shabaab group claimed responsibility for the attack, according to the group's Andalus radio. Both foreigners and Somalis were casualties of the attack in Garowe, the capital of the semiautonomous Puntland region, Col. Ali Salad, a senior police officer in Puntland, told The Associated Press by phone. A UN employee in Garowe, who insisted upon anonymity because she was not authorized to speak to the press, said most of the victims are foreigners working with the UN She said they were traveling early on Monday in a bus that belonged to the UN children's agency, UNICEF. The UN representative to Somalia, Nicholas Kay, said in a Twitter post that he is “shocked and appalled by loss of life.” The bomb was apparently planted under a seat and was detonated by remote control, said police official Yusuf Ali. Garowe resident Jama Hashi said he heard a thundering blast inside the bus, which he said was passing near the offices of the UN's food agency when the bomb went off. Human limbs were scattered around the scene, he said. Security forces sealed off the area as ambulances carried the wounded away. “It's a dark day, but terrorists must know that the blood they shed will not go in vain. We shall deal with them with an iron hand,” Salad said. Bomb attacks are not common in the northern parts of Somalia, unlike in the south where al-Shabab militants are waging a deadly war against the Western-backed Somali government and the African Union forces bolstering it. Last week at least 10 people were killed in an assault on the offices of Somalia's education ministry. The attacks often target he seat of government in the Somali capital, Mogadishu, as well as public places known to be popular with foreigners living in Somalia. Despite losing a lot of ground in recent times and losing top leaders in US airstrikes, Al-Shabaab militants are still able to launch attacks in different parts of Somalia and even across borders, especially in Kenya. Al-Shabaab claimed responsibility for an attack ealier this month at a university campus in northeastern Kenya in which militants killed 148 people, most of them students. — AP