At least 10 people have been killed by a mortar bomb blast at a mosque in the Somali capital Mogadishu, say reports. It was unclear clear who fired the mortar but it came as pro-government forces continued to battle radical Islamist guerrillas in the city. The fighting has killed more than 250 people - civilians and combatants - since it erupted last month. Earlier, Mogadishu's police chief was reported to have been killed during an attack on insurgent bases. BBC East Africa correspondent Will Ross says the death of Colonel Ali Said will be a significant setback for the pro-government forces, as he had often been on the front line encouraging his colleagues to defend their positions. Dadir Ali Jes, who witnessed the mosque attack, said he believed at least 13 people had been killed in what he said was "the most terrible incident". As well as those killed, more than 120,000 people have been displaced in the latest upsurge of violence, the United Nations says . Meanwhile UNICEF, the UN's children's agency, says Islamist fighters have looted its supplies being held in the southern Somali town of Jowhar. Hannan Sulieman, Unicef's acting Somalia representative, said the UN workers "strongly urge that humanitarian work not be impeded in any way", and called for the immediate release of looted supplies. Somalia has not had an effective national government since 1991 and some four million people - a third of the population - need food aid, aid agencies say. Source: BBC