Shark stalks Sydney swimming race 
The shark was chased away by boatsMore than 20 swimmers were hauled from the water during an ocean swimming race in Australia when a three-metre-long shark started stalking swimmers.
The 10km (six-mile) Cole Classic race off Sydney's Manley Beach was abandoned halfway, local media reports said.
Twenty-one swimmers were picked up by boats and jet skis while other boats chased the shark away, organisers said.
The rescue came weeks after three sharks killed a 21-year-old Australian woman off Brisbane.
'Mass evacuation'
"The shark was on the surface so the best thing we could do was start a mass evacuation straight away," race director Stephen Ford told Australia's Daily Telegraph newspaper.
The race involved some of Australia's top long-distance swimmers. The shark's dorsal fin was seen slicing through the water behind the swimmers.
The woman who died off Brisbane in January was the 10th to be killed by a shark in Australian waters since 2000.
In September of last year a surfer fought a five-metre-long (15 ft) great white shark in waters of South Australia's Kangaroo Island.
"Are you sure we're going fast enough?" - Emil Zatopek
The shark was chased away by boatsMore than 20 swimmers were hauled from the water during an ocean swimming race in Australia when a three-metre-long shark started stalking swimmers. The 10km (six-mile) Cole Classic race off Sydney's Manley Beach was abandoned halfway, local media reports said.
Twenty-one swimmers were picked up by boats and jet skis while other boats chased the shark away, organisers said.
The rescue came weeks after three sharks killed a 21-year-old Australian woman off Brisbane.
'Mass evacuation'
"The shark was on the surface so the best thing we could do was start a mass evacuation straight away," race director Stephen Ford told Australia's Daily Telegraph newspaper.
The race involved some of Australia's top long-distance swimmers. The shark's dorsal fin was seen slicing through the water behind the swimmers.
The woman who died off Brisbane in January was the 10th to be killed by a shark in Australian waters since 2000.
In September of last year a surfer fought a five-metre-long (15 ft) great white shark in waters of South Australia's Kangaroo Island.
"Are you sure we're going fast enough?" - Emil Zatopek