Two crew members participating in the Sydney to Hobart yacht race in Australia are dead after separate accidents at sea, police announced late Thursday.

The Cruising Yacht Club of Australia in Sydney said Friday that one sailor each on entrants Flying Fish Arctos and Bowline were killed after being struck by the boom, a large horizontal pole at the bottom of the sail.

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