(CNN) -- A shark bit a 16-year-old boy across both legs as he was surfing in Hawaii on Sunday, CNN affiliate KHON reported.
The attack came four days after a shark severed the right arm of a German tourist while she was snorkeling.
In the Sunday incident, the teen was surfing in Pohoiki Bay when an 8-foot gray shark attacked him, the affiliate reported.
He was taken to a hospital, but his condition was not known.
Authorities brought in helicopters to survey the area for sharks, but were unsuccessful.
This shark attack is the fourth in the last month, and 9th for the year in Hawaii, the affiliate said.
Last year, Hawaii had 11 shark attacks.
While shark attacks have been on the uptick in recent years, according to the University of Florida, the fatality rate in the United States is just 2%.