The reports of attacks on commercial ships came after the US said it "eliminated" 16 Iranian mine-layers in the area.
The Israeli military says it's responding to strikes from Iran-backed Hezbollah, and warns residents in Beirut's southern suburbs to evacuate.
The US says the ships were targeted in the Strait of Hormuz - a key shipping route. In Dubai, authorities say the airport is operating normally after two drones were downed in the area.