A charter bus carrying a US college baseball team from Ohio plunged off a motorway ramp today and slammed into the pavement below, killing six people and injuring 29, authorities said.

At least six people were killed when a US charter bus carrying a college baseball team from Ohio plunged off an Atlanta slip road early today.

Police in America tonight defended the actions of an officer who allegedly knocked a distinguished British historian to the ground after he crossed the road in the wrong place.

A police official today said narcotics officers in the US were justified in returning fire on a 92-year-old woman they shot dead after she shot them as they tried to serve a warrant at her house.