A bus bomb blast near the Ugandan city of Lungala has killed at least two people, police say.  

The cause of the explosion on the main road between Kampala and Masaka is not yet known, confirmed to Reuters military sources in Uganda.  

Earlier in the day, Ugandan police said they were investigating whether members of the Islamic State terrorist group carried out the bombing following Saturday's attack in Kapmala, which killed one person and injured three.  

Islamic State claimed responsibility for Sunday's bombing in Kampala, Uganda's capital. The group said some of its members had detonated an explosive device at a bar where "members and spies of the Ugandan crusader government were gathering".  

Information gathered during the investigation confirms that three men, disguised as guests, visited the restaurant and left a plastic bag under the table and left the building just moments before the explosion.