Officials say a roadside bomb has hit a police vehicle in southern Afghanistan, killing two policemen and wounding three others. Kandahar province police commander Sahib Jan says the remote-controlled bomb went off Tuesday on the main highway in Spin Boldak district. One of the injured policemen was in critical condition. The attack comes a day after insurgents killed 11 police in nearby Arghandab district. Militants killed more than 900 police officers last year. Police are frequent targets because they have less training and weaponry and they work in smaller teams than Afghan or NATO soldiers.