A gunman has killed 12 people in a mass-shooting in the US.

Police say a disgruntled employee fired "indiscriminately" at victims at a public-utility company in Virginia Beach.

Four people were also injured in the attack, including a police officer, before the suspect was shot dead by officers.

The city's mayor, Bobby Dyer, summed up the mood at the popular holiday spot.

He said: "This is the most devastating day in the history of Virginia Beach.

"The people involved are our friends, co-workers, neighbours, colleagues."