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.

Two sailors have been killed in separate incidents in the treacherous Sydney to Hobart yacht race, officials said on Friday, as a string of yachts retired in powerful winds and high seas.

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