Denpasar – An American surfer has been mauled by a two-metre shark off the Indonesian resort island of Bali, sustaining a serious arm injury, a doctor said on Wednesday.Ryan Boarman, in his 20s, was admitted to hospital in the west of the holiday island on Monday shortly after being attacked by the shark as he surfed at Balian beach.While shark attacks are generally rare in Bali there have been several such incidents in recent years at Balian, a popular surfing spot.Doctor Ni Gusti Ayu Made Sri Pujarini, who initially treated Boarman at a local hospital, said he was conscious when brought in."He said that he saw a two-metre shark just before he felt the pain," she told AFP. "His wounds were consistent with shark bite injuries, you could see the teeth marks."Pujarini said he underwent emergency surgery and was then transferred to a bigger hospital in the Balinese capital Denpasar.Twiggy Van Ryan, an Australian who lives near Balian, described how he saw Boarman shortly after the attack and helped dress his wound before he was taken to hospital."It was a pretty heavy wound, maybe four inches (10cm) either side of the tip of the elbow, basically his whole elbow had gone into the shark's mouth and then was pretty badly damaged as the shark pulled back," he said.Between 2010 and 2012, there were at least four reports of foreigners, including a Canadian, an Australian and a South African, being attacked by sharks around the beach.