US forces sealed off a house in the northern city of Mosul where eight suspected al-Qaida members died in a gunfight - some by their own hand to avoid capture. A US official said Sunday that efforts were under way to determine if terror leader Abu Musab al-Zarqawi was among the dead. Insurgents, meanwhile, killed an American soldier and a Marine in separate attacks over the weekend, while a British soldier was killed by a roadside bomb in the south. In Washington, a US official said the identities of the terror suspects killed was unknown. Asked if they could include al-Zarqawi, the official replied: "There are efforts under way to determine if he was killed." The official spoke on condition of anonymity because of the sensitivity of the information.