Two sailors have been killed during the Sydney to Hobart yacht race amid a night of tough weather conditions that hit the fleet.

Two sailors on separate boats have been killed in boom accidents two hours apart on a storm-ravaged first night of the annual Sydney to Hobart race, adding to the event’s long history of deaths at sea.

The men were hit in the head by booms on their yachts in separate episodes, as participants faced challenging weather conditions, the police said.