Four people have been killed and 12 others injured, four critically, after a mass shooting in the US state of Mississippi. The shooting happened at around midnight on the main street in Leland, 120 miles (190km) north-east of the state capital Jackson, the city's mayor John Lee told the BBC's US partner CBS. Four of the injured were airlifted to hospital, he added. There were no suspects in custody. Leland was busier than usual on Friday with the local high school scheduled to play a football game to mark homecoming, an annual US tradition, usually in autumn, when former students are welcomed back to celebrate school spirit and community.