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 a 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.