Beaches at the Australian city of Newcastle were closed for a seventh day on Friday after at least two large sharks were sighted in coastal waters. Meanwhile, a teenage spear fisher was attacked by a shark 390 kilometers (240 miles) to the south.

A 5-meter (16-foot) great white shark estimated to weigh 1.7 metric tons (1.9 tons) had been spotted daily since last Saturday until Thursday off the coast of Newcastle, a city of 315,000 people 160 kilometers (100 miles) north of Sydney, Newcastle City Council said.

At Ulladulla, a coastal town 230 kilometers (140 miles) south of Sydney, a 17-year-old boy was attacked by a shark.

Paramedics treated the boy for lacerations to his hand and fingers, ambulance service spokeswoman Jackie Levett said. The boy was taken to a hospital in a satisfactory condition, she said.

Luke Sisinni, who was diving with the boy identified as Sam Smith, said his friend was attacked while attempting to video a 1.5-meter (5-foot) shark.

"He said it spun around and started coming for him, so he stabbed it with his spear to try and scare it off, but it just went ballistic and bit him," Sisinni told The Milton Ulladulla Times news website.

Nearby Narrawellee Beach was closed following the attack. However, hundreds of volunteer lifeguards continued to compete in a championship competition 2 kilometers (1.25 miles) away at Mollymook Beach.

In Newcastle, photographs appeared in Australian media of a 3.5-meter (11-foot) shark mauling a dolphin on Thursday off Burwood Beach, 200 meters (yards) from where divers were ignoring the beach closure by spearing fish.

A 3.5-meter shark was again spotted off the same beach on Friday morning, the council said in a statement. It was not clear what type of shark it was or whether it was the same shark as attacked the dolphin.

Lifeguards were working long shifts to warn beachgoers to stay out of the water, and long-term employees of the council could not recall sharks closing city beaches for so long.

The beach closure comes during peak tourist season with schools closed for the summer vacation.

Danny Bucher, a Southern Cross University marine biologist, expected the great white shark would eventually leave Newcastle.

"As a general rule they're nomadic, but if there's a reliable supply of food, they'll hang around while that food lasts," Bucher said.