At a gay pride parade in the US state of Florida, the driver of a pickup truck drove into the crowd and killed at least one man.
US media reported it was unclear whether the incident at Wilton Manors near Fort Lauderdale was a deliberate attack.
The van driver was provisionally arrested.
The van initially joined the parade for the rights of LGBT people, reported the local broadcaster Local 10 News.
But then he accelerated and knocked over at least two men.
One of them died, said Fort Lauderdale Mayor Dean Trantalis, who attended the parade.
According to him, the van had driven towards the convertible belonging to Democratic Congressman Debbie Wasserman Schultz, but had missed the car.
Trantalis was convinced that it was a deliberate act, namely "a terrorist attack against the LGBT community".
The English abbreviation LGBT stands for lesbian, gay, bisexual and transgender.