At least six people died and at least nine were injured in an early-morning shooting in Sacramento, California, the city's police department said on Twitter.
Police said several blocks of a commercial stretch of the downtown area were closed while they investigate. Videos posted online showed people shouting and running in the street.
Reuters could not independently verify the footage.
The incident comes a little more than a month after a man shot and killed his three children and a fourth person before taking his own life in the same city.
India begins voting in election as Modi seeks historic third term
Teenager charged with terrorism over Sydney bishop stabbing
Kenya's military chief among 10 killed in helicopter crash
Security Council to vote on Palestinian UN membership
Toll from Russia's deadliest airstrike on Ukraine in weeks rises to 18
