At least four people died Saturday when a helicopter carrying photographers crashed near the port in the city of Rotterdam, police said. Witnesses reported that the machine, a Eurocopter EC130, "fell straight down" into dunes adjacent to the North Sea. Three of the five passengers died immediately and a fourth later succumbed to injuries in hospital. Police have not yet identified the victims, dpa reported. No cause of the crash has yet been ascertained. The aircraft had been chartered for a photography tour of the harbour in connection with a cycle race, which was immediately broken off, a port spokesman said.