A shooting has taken place in the US state of Maryland, renewing fears that a sniper is still operating in the area. A 40-year-old bus driver was hit in the chest by a single bullet in the early hours of Tuesday morning on the steps of his bus in the Aspen Hill area of Montgomery County, on the outskirts of Washington. The shooting occurred on a main road, Connecticut Avenue, about 25 kilometres (15 miles) north of the US capital just before 0600 local time (1000 GMT). The road has now been cordoned off by police, causing heavy traffic jams during rush hour, and surveillance helicopters are circling overhead.